Miracle-dz/UniFAR-FTUs huggingface dataset:
Cosmological Horizon and the Quadrupole Formula in de Sitter Background

An important class of observables for gravitational waves consists of the fluxes of energy, momentum and angular momentum carried away by them and are well understood for weak gravitational waves in Minkowski background. In de Sitter background, the future null infinity, $\mathcal{J}^+$, is space-like which makes the meaning of these observables subtle. A Spatially compact source in de Sitter background also provides a distinguished null hypersurface, its cosmological horizon, $\mathcal{H}^+$. For sources supporting the short wavelength approximation, we adopt the Isaacson prescription to define an effective gravitational stress tensor. We show that the fluxes computed using this effective stress tensor can be evaluated at $\mathcal{H}^+$ and match with those given by Ashtekar et al at $\mathcal{J}^+$.
On planet formation in HL Tau

We explain the axisymmetric gaps seen in recent long-baseline observations of the HL Tau protoplanetary disc with the Atacama Large Millimetre/Submillimetre Array (ALMA) as being due to the different response of gas and dust to embedded planets in protoplanetary discs. We perform global, three dimensional dusty smoothed particle hydrodynamics calculations of multiple planets embedded in dust/gas discs which successfully reproduce most of the structures seen in the ALMA image. We find a best match to the observations using three embedded planets with masses of 0.2, 0.27 and 0.55 MJ in the three main gaps observed by ALMA, though there remain uncertainties in the exact planet masses from the disc model.
A novel interactive technique for load current harmonic reduction for any randomly utilized household equipment

Sustaining a stable level of power quality in the localized network is a growing challenge due to the increased use of power electronics. This paper proposes a novel interactive technique that reads the load current according to the connected loads. Whenever equipment is started running, the system is immediately read the distorted current for three cycles. The fundamental current can be estimated according to the system acquired readings. This system subtracts this estimated fundamental current from the sensor current reader to extract the total harmonic currents. According to the total harmonic currents the system uses suitable switching frequency Fs and modulation index Ma for generating anti-current source inverter (CSI) pulse width modulation (PWM) signal. Complete and comprehensive comparison between the system laboratory measurements using the Calmet TE30 power analyzer and the simulation model are presented. These results confirmed significant agreements between the proposed model and actual measurements at different loads. Furthermore, current and voltage sensors accompanied with a microcontroller read the load current the system realization. Finally, the measured currents of different loads are almost typically confirmed with the power analyzer's results. The reduced harmonics currents of the implemented model display the system validation.
Job Insecurity and Intention to Quit: The Role of Psychological Distress and Resistance to Change in the UAE Hotel Industry

Hotel organizations today are in a state of constant change due to high competition, the emergence of pandemics, and cyclical economic crises. Hospitality employees are currently affected by job insecurity. The purpose of this research was to investigate the effect of job insecurity on intention to quit among hospitality workers, integrating the mediating effect of psychological distress and resistance to change and their mutual relationship. A total of 312 surveys were completed in four four- and five-star hotels in the UAE (Dubai and Sharjah). The SmartPLS 4 software was used to test the hypotheses in a mediation model with the bootstrapping method. The results showed that all of the direct links were positive and significant, and mediating relationships were confirmed. This study found that job insecurity predicts intention to quit through psychological distress and resistance to change acting as mediators, and these factors themselves also impact significantly on intention to quit. Resistance to change is impacted significantly by job insecurity and psychological distress, which suggests that a deeper approach to employees’ resistance to change should be taken, especially when conducting performance appraisals in the hotel industry, by searching for its roots and aiming to minimize employees’ intention to quit.
Computation of maximum power point tracking of PV module using modified Newton Raphson technique

The maximum power point tracking (MPPT) has been a popular terminology among those researchers who deal with one of the most available renewable energy resources called solar power. Many researchers have evolved and proposed a lot of techniques for tracking maximum power. But each technique has its pros and cons. Some techniques suffer from complexity as far as implementation is concerned, whereas other techniques lack accuracy. In current research work, it has been investigated the MPPT using Newton Raphson (NR) method, which has not yet received a good attention by researchers. After observing its limitation, this method is modified (i.e., abbreviated as modified Newton Raphson method (MNRM)) to make it suitable for extracting the maximum power from PV module. The feasibility and precision of this method depends upon accurate measurement of temperature and irradiation. By using MNRM, the presumption of initial value is close to the voltage corresponding to maximum power, so it leads faster converging to solution through a few rounds of iterations. In order to validate it, a MATLAB/Simulink model is developed and simulated. The proposed method is incorporated in PV module-fed buck converter so as to explore superior performance.
Martingale Strategy for Modeling Quantum Adiabatic Evolution

We propose a strategy for modeling the behavior of an adiabatic quantum computer described by an Ising Hamiltonian with $N$ sites and the coordination number $Z$. The method is based on the $1/Z$ expansion for the density matrix of the system. In each order, the ground state energy is found neglecting the higher-order correlations between the sites, as long as the set of equations remains non-singular. The conditions of the appearance of a singularity, equivalent to the disappearance of energy gap in the given approximation, can be directly obtained from the equations. Then the next order in the expansion must be used, at the price of an $N$-fold increase in computational resources. This "martingale" strategy allows reducing the computational costs to a power of $N$ rather than $2^N$, with a finite probability of success. The strategy is illustrated by the case of a two-spin system and extended to a large number of qubits. Comparing the predictions to the experimental results obtained by using an adiabatic quantum computer would help quantify the importance of multi-site correlations, and the influence of decoherence, on its operation.
Postoperative Hypocalcemia following Non-Cardiac Surgical Procedures in Children with 22q11.2 Deletion Syndrome

The guidelines for management of children with 22q11.2 deletion syndrome (22q11DS) highlight the risk for developing hypocalcemia after surgery and recommend monitoring calcium perioperatively. Despite this guidance, little has been published on postoperative hypocalcemia and 22q11DS. Our goals were to evaluate the frequency of perioperative calcium monitoring and examine how often postoperative hypocalcemia was identified. This is a retrospective chart review of patients in our 22q Center’s repository. Inclusion criteria were a diagnosis of 22q11DS and a history of a non-cardiac surgical procedure. Data collected included all non-cardiac surgeries and perioperative calcium labs. In total, 68 patients were included and underwent 305 on-cardiac surgeries. Patients in only 17% of these surgeries had postoperative calcium testing, but of those tested, 58% showed hypocalcemia. Patients with history of hypocalcemia at the time of chart review undergoing non-cardiac surgeries were tested postoperatively 40% of the time; however, 67% of these had hypocalcemia. Similarly, for patients without history of hypocalcemia, postoperative testing occurred 60% of the time, with 52% of these having hypocalcemia. This study demonstrates that postoperative hypocalcemia in children with 22q11DS following non-cardiac surgeries is common and affects patients both with and without prior history of hypocalcemia. These data support establishing a protocol for perioperative testing/management of hypocalcemia for patients with 22q11DS.
Modelling Stellar Populations at High Redshift

Abstract Stellar populations carry information about the formation of galaxies and their evolution up to the present epoch. A wealth of observational data are available nowadays, which are analysed with stellar population models in order to obtain key properties such as ages, star formation histories, stellar masses. Differences in the models and/or in the assumptions regarding the star formation history affect the derived properties as much as differences in the data. I shall review the interpretation of high-redshift galaxy data from a model perspective. While data quality dominates galaxy analysis at the highest possible redshifts (z > 5), population modelling effects play the major part at lower redshifts. In particular, I discuss the cases of both star-forming galaxies at the peak of the cosmic star formation history as well as passive galaxies at redshift below 1 that are often used as cosmological probes. Remarks on the bridge between low and high-z massive galaxies conclude the contribution.
Low Arousal Threshold Estimation Predicts Failure of Mandibular Advancement Devices in Obstructive Sleep Apnea Syndrome

Introduction: The treatment of choice for obstructive sleep apnea syndrome (OSAS) is continuous positive airway pressure (CPAP). However, CPAP is usually poorly tolerated and mandibular advancement devices (MADs) are an alternative innovative therapeutic approach. Uncertainty still remains as to the most suitable candidates for MAD. Herein, it is hypothesized that the presence of low arousal threshold (low ArTH) could be predictive of MAD treatment failure. Methods: A total of 32 consecutive patients, with OSAS of any severity, who preferred an alternate therapy to CPAP, were treated with a tailored MAD aimed at obtaining 50% of their maximal mandibular advancement. Treatment response after 6 months of therapy was defined as AHI < 5 events per hour or a reduction of AHI ≥ 50% from baseline. Low ArTH was predicted based on the following polysomnography features, as previously shown by Edwards et al.: an AHI of 82.5% and a hypopnea fraction of total respiratory events of >58.3%. Results: There were 25 (78.1%) responders (p-value < 0.01) at 6 months. Thirteen patients (40.6%) in the non-severe group reached AHI lower than 5 events per hour. MAD treatment significantly reduced the median AHI in all patients from a median value of 22.5 to 6.5 (74.7% of reduction, p-value < 0.001). The mandibular advancement device reduced AHI, whatever the disease severity. A significant higher reduction of Delta AHI, after 6 months of treatment, was found for patients without low ArTH. Conclusions: Low ArTH at baseline was associated with a poorer response to MAD treatment and a lower AHI reduction at 6 months. A non-invasive assessment of Low ArTH can be performed through the Edwards’ score, which could help to identify an endotype with a lower predicted response to oral appliances in a clinical setting.
Special Issue: The adaptive nature of linguistic behavior

Not just diachronic change or synchronic variability in linguistic structure, but also the shape of speakers’ expressive strategies for navigating natural verbal interaction can be seen as reflections of the fundamental human capacity for adapting to novel communicative circumstances. The adjustments are observable at all layers of language — sounds, prosody, lexical changes, shifts in grammatical organization — and also pose questions concerning adaptation at both the individual and community levels. In this introductory framing of the present volume, the conceptual underpinnings of the quest for adequate explanations of adaptive processes are consistent with a set of assumptions that are associated with, broadly speaking, ‘socio-cognitive’ approaches to language: (i) socio-prag-matic and cultural grounding of verbal interaction, (ii) reference to domain-general cognitive capacities, and (iii) emergence of linguistic categories and their organization from recurring patterns of use. Linguistic analysis focused on the adaptive aspects of language and language use thus aims at capturing the speakers’ interactional competence; this includes both narrowly linguistic aspects and non-linguistic patterns of behavior, which, taken together, help us understand better all the factors involved in successful communication.
Transformation optics approach to singular metasurfaces

Surface plasmons dominate the optical response of metal surfaces, and their nature is controlled by surface geometry. Here we study metasurfaces containing singularities in the form of sharp edges and characterized by three quantum numbers despite the two-dimensional nature of the surface. We explore the nature of the plasmonic excitations, their ability to generate large concentrations of optical energy, and the transition from the discrete excitation spectrum of a non-singular surface to the continuous spectrum of a singular metasurface.
Dual Band Rectenna for Wireless Energy Harvesting in the 2.40 GHz and 5.38 GHz

The objective of this study, reflected in this document, was to implement a rectenna for 2.45 GHz and 5.38 GHz wireless local area applications. For this purpose, the antenna dimensions were set to 18 mm × 44 mm, which is simulated using the optimization software CST Studio, manufactured on FR4 substrate with a thickness of 1.6 mm, where the conductive material has a thickness of 0.035 mm. Likewise, the rectangular slot technique was used to improve the bandwidth of the antenna; this technique consists of inserting slots in the structure to modify the displacement of the surface current. The above presented a gain of 2.49 dB at the 2.45 GHz frequency and 4.01 dB at the 5.38 GHz frequency. The proposed antenna for RF energy harvesting applications exhibits a dipole type radiation pattern, which enhances the capture of RF energy from various directions. The triple slotted-band rectifier with T-shaped impedance matching network was designed in FR4, using a Schotkky HSMS-286C diode for AC to DC RF control switching. A tp-link TL-WR940N wireless router was used as the RF emitting source at 30 cm separation between it and the proposed rectenna. The DC output of the rectenna is 3 volts with a generated signal power of 20 dBm at 2.4 GHz. The low-cost rectenna can be used for power-charging applications in the Internet of things (IoT) systems.
Exchange arrangements and economic growth. What relationship is there?

This article provides empirical support for the hypothesis that different exchange rate regimes have an impact on economic growth in advanced, emerging and developing countries. The effects of different exchange rate arrangements on economic growth are examined through least squares dummy variable regressions using panel data on 125 countries during the post-Bretton Woods period (1974-1999). Also, this article addresses the issue of measurement errors in the classification of exchange rate regimes by using four different classification schemes. Three de facto and one de jure classifications are used. Consequently, the sensitivity of these results to alternative exchange rate classifications is also tested. The empirical findings indicate that developing countries with fixed regimes tend to have a higher economic growth.
A Hypothetical Effect of the Maxwell–Proca Electromagnetic Stresses on Galaxy Rotation Curves

Maxwell–Proca electrodynamics corresponding to finite photon mass causes a substantial change in the Maxwell stress tensor, and under certain circumstances, may cause electromagnetic stresses to act effectively as “negative pressure. ” This paper describes a model where this negative pressure imitates gravitational pull and may produce forces comparable to gravity and may even become dominant. The effect is associated with random magnetic fields with correlation lengths exceeding the photon Compton wavelength. The stresses act predominantly on the interstellar gas and cause an additional force pulling the gas toward the center and toward the galactic plane. Stars do not experience any significant direct force but get involved in this process via a “recycling loop,” where rapidly evolving massive stars are formed from the gas undergoing galactic rotation and then lose their mass back to the gas within a time shorter than roughly 1/6 of the rotation period. This makes their dynamics inseparable from that of the rotating gas. As soon as the lighter, slowly evolving stars are formed, they lose their connection to the gas and are only gravitationally confined within the galaxy. Peculiarities in the dynamics of these slowly evolving stars may serve as an experimental test of the presence and magnitude of the Maxwell–Proca stresses. In fact, observational data for Sun-like stars in our galaxy appear to be incompatible with the assumption of the Maxwell–Proca stresses contributing at a level needed to explain the galactic rotation curve, although they could contribute a 10%–20% addition to the observed centripetal pull. It may be interesting to also explore possible broader cosmological implications of the negative-pressure model.
Holographic baryonic matter in a background magnetic field

We discuss the effect of baryonic matter on the zero-temperature chiral phase transition at finite chemical potential in the presence of a background magnetic field. The main part of our study is done in the deconfined geometry of the Sakai–Sugimoto model, i.e. at large Nc and strong coupling, with non-antipodal separation of the flavor branes. We find that for not too large magnetic fields baryonic matter completely removes the chiral phase transition: chirally broken matter persists up to arbitrarily large chemical potential. At sufficiently large magnetic fields, baryonic matter becomes disfavored and mesonic matter is directly superseded by quark matter. In order to discuss the possible relevance of our results to quantum chromodynamics, we compute the baryon onset in a relativistic mean-field model including the anomalous magnetic moment and point out the differences to our holographic calculation.
Two extensions of exact nonequilibrium steady states of a boundary-driven cellular automaton

Recently Prosen and Mejía-Monasterio (2016 J. Phys. A: Math. Theor. 49 185003) obtained exact nonequilibrium steady states of an integrable and reversible cellular automaton driven by some stochastic boundary conditions. In this paper, we explore the possible extensions of their method by generalizing the boundary conditions. As the result, we find two cases where such an extension is possible. One is obtained by generalizing probabilities for values of virtual cells while imposing a special condition on emission and absorption rates. Although this actually coincides with the conditional boundary driving discussed in Prosen and Buča (2017 J. Phys. A: Math. Theor. 50 395002), we present a solution in a different form. The other is obtained by considering a conserved quantity as energy, and by considering boundaries as heat reservoirs. The latter contains the original solution and the former one as the special cases. Properties of both solutions are discussed.
Quasi-periodic oscillations, trapped inertial waves, and strong toroidal magnetic fields in relativistic accretionwhen th discs

The excitation of trapped inertial waves (r-modes) by warps and eccentricities in the inner regions of a black hole accretion disc may explain the high-frequency quasi-periodic oscillations (HFQPOs) observed in the emission of Galactic X-ray binaries. However, it has been suggested that strong vertical magnetic fields push the oscillations' trapping region toward the innermost stable circular orbit (ISCO), where conditions could be unfavourable for their excitation. This paper explores the effects of large-scale magnetic fields that exhibit \textit{both} toroidal and vertical components, through local and global linear analyses. We find that a strong toroidal magnetic field can reduce the detrimental effects of a vertical field: in fact, the isolation of the trapping region from the ISCO may be restored by toroidal magnetic fields approaching thermal strengths. The toroidal field couples the r-modes to the disc's magneto-acoustic response and inflates the effective pressure within the oscillations. As a consequence, the restoring force associated with the vertical magnetic field's tension is reduced. Given the analytical and numerical evidence that accretion discs threaded by poloidal magnetic field lines develop a strong toroidal component, our result provides further evidence that the detrimental effects of magnetic fields on trapped inertial modes are not as great as previously thought.
HIGH RESOLUTION OBSERVATIONS OF CHROMOSPHERIC JETS IN SUNSPOT UMBRA

Recent observations of a sunspot's umbra have suggested that it may be finely structured on a subarcsecond scale representing a mix of hot and cool plasma elements. In this study, we report the first detailed observations of umbral spikes, which are cool jet-like structures seen in the chromosphere of an umbra. The spikes are cone-shaped features with a typical height of 0.5–1.0 Mm and a width of about 0.1 Mm. Their lifetime ranges from 2 to 3 minutes and they tend to re-appear at the same location. The spikes are not associated with photospheric umbral dots and they instead tend to occur above the darkest parts of the umbra where magnetic fields are strongest. The spikes exhibit up and down oscillatory motions and their spectral evolution suggests that they might be driven by upward propagating shocks generated by photospheric oscillations. It is worth noting that triggering of the running penumbral waves seems to occur during the interval when the spikes reach their maximum height.
Embedded Silicon-Organic Integrated Neuromorphic System

The development of artiﬁcial intelligence (AI) and robotics are both based on the tenet of "science and technology are people-oriented", and both need to achieve efﬁcient communication with the human brain. Based on multi-disciplinary research in systems neuroscience, computer architecture, and functional organic materials, we proposed the concept of using AI to simulate the operating principles and materials of the brain in hardware to develop brain-inspired intelligence technology, and realized the preparation of neuromorphic computing devices and basic materials. We simulated neurons and neural networks in terms of material and morphology, using a variety of organic polymers as the base materials for neuroelectronic devices, for building neural interfaces as well as organic neural devices and silicon neural computational modules. We assemble organic artiﬁcial synapses with simulated neurons from silicon-based Field-Programmable Gate Array (FPGA) into organic artiﬁcial neurons, the basic components of neural networks, and later construct biological neural network models based on the interpreted neural circuits. Finally, we also discuss how to further build neuromorphic devices based on these organic artiﬁcial neurons, which have both a neural interface friendly to nervous tissue and interact with information from real biological neural networks.