Miracle-dz/UniFAR-FTUs huggingface dataset:
EHT observables as a tool to estimate parameters of supermassive black holes

The Event Horizon Telescope (EHT) collaboration unveiled event-horizon-scale images of the supermassive black holes (SMBHs) M87* and Sgr A*, revealing a dark brightness depression, namely the black hole shadow, whose shape and size may encode the parameters of the SMBHs, and the shadow is consistent with that of a Kerr black hole. It furnishes another encouraging tool to estimate black hole parameters and test theories of gravity in extreme regions near the event horizon. We propose a technique that uses EHT observables, the angular shadow diameter dsh and the axis ratio $\mathcal {D}_A$, to estimate the parameters associated with SMBHs, described by the Kerr metric. Unlike previous methods, our approach explicitly considers the uncertainties in the measurement of EHT observables. Modelling Kerr–Newman and three rotating regular spacetimes to be M87* and Sgr A* and applying our technique, we estimate the associated charge parameters along with spin. Our method is consistent with the existing formalisms and can be applied to shadow shapes that are more general and may not be circular. We can use the technique for other SMBHs once their EHT observables become accessible. With future, more accurate measurements of the EHT observables, the estimation of various SMBH parameters like the spin and inclination angles of M87* and Sgr A* would be more precise.
Sensitivity analysis for III–V/Si tandem solar cells: A theoretical study

Material and structural parameters may affect the efficiency of a tandem solar cell differently from the way they do in a single-junction solar cell. We fabricated a III–V/Si four-terminal tandem solar cell and developed an opto-electronic model simulating this device. The optical properties were simulated with the transfer matrix method, while the electrical properties were simulated using the numerical device simulator PC1D. For this simulated tandem structure, we determined the parameters which have the largest potential impact on the device efficiency. A sensitivity analysis of the impact of these parameters on the device efficiency was also performed. In addition, to reduce the cost of the tandem solar cells, we identified the parameters that do not require tight control during the manufacturing process. The Si cell was simulated both as a single-junction cell and as the bottom cell of a tandem device. Finally, we determined those device parameters that are more critical in a tandem configuration than in a single-junction configuration.
A modular adaptive control design with ISS analysis for nonminimum phase hypersonic vehicle models

Air‐breathing hypersonic vehicles typically exhibit a nonminimum phase behavior when altitude is controlled via lift generation. This phenomenon prohibits the use of classical inversion‐based control techniques. Dynamic models of these vehicles are also subject to parametric uncertainties and unmodeled dynamics related to flexible effects of the fuselage. In this paper, we present a modular adaptive control method that achieves asymptotic setpoint tracking in both airspeed and altitude using thrust and elevator deflection as the only control inputs for a generic longitudinal model of a hypersonic cruise. The nonminimum phase problem is overcome through output redefinition, with altitude controlled by pitching moment. The internal dynamics, flight path angle, and altitude are then stabilized by saturating the interconnections and exploiting local stability properties. A new technique for the use of saturation functions in error coordinate is presented. The adaptive controller for altitude uses a pitch rate observer combined with projection. This control augmentation decouples the parameter estimation errors from internal dynamics, allowing for the use of small‐gain arguments. Simulation results from a vehicle model with flexible effects and parametric uncertainty are included to demonstrate control effectiveness.
Recombination velocity less than 100 cm/s at polycrystalline Al2O3/CdSeTe interfaces

Reducing recombination in polycrystalline solar cells by orders of magnitude is currently one of the greatest challenges for increasing thin-film solar cell efficiency to theoretical limits. The question of how to do this has been a challenge for the thin-film community for decades. This work indicates that effective interface passivation is critical. Here, polycrystalline Al2O3/CdSeTe/Al2O3/glass heterostructures are grown, and a combination of spectroscopic, microscopic, and time-resolved electro-optical measurements demonstrates that the interface recombination velocity at alumina/thin-film interfaces can be less than 100 cm/s. This is three orders of magnitude less than typical CdTe interfaces without passivation, commensurate with single-crystal epitaxial CdMgSeTe/CdSeTe/CdMgSeTe double heterostructures, and enables minority-carrier lifetimes in polycrystalline CdSeTe well above 100 ns. Microscopic interfacial electric-field measurements identify the field effect as a potential mechanism for polycrystalline Al2O3/CdSeTe interface passivation. The results provide guidance for modeling and interface passivation in devices and indicate future paths to realize highly efficient thin-film solar cells.Reducing recombination in polycrystalline solar cells by orders of magnitude is currently one of the greatest challenges for increasing thin-film solar cell efficiency to theoretical limits. The question of how to do this has been a challenge for the thin-film community for decades. This work indicates that effective interface passivation is critical. Here, polycrystalline Al2O3/CdSeTe/Al2O3/glass heterostructures are grown, and a combination of spectroscopic, microscopic, and time-resolved electro-optical measurements demonstrates that the interface recombination velocity at alumina/thin-film interfaces can be less than 100 cm/s. This is three orders of magnitude less than typical CdTe interfaces without passivation, commensurate with single-crystal epitaxial CdMgSeTe/CdSeTe/CdMgSeTe double heterostructures, and enables minority-carrier lifetimes in polycrystalline CdSeTe well above 100 ns. Microscopic interfacial electric-field measurements identify the field effect as a potential mechanism for polycrys.
Distributed event-triggered consensus control for multiple Lur'e nonlinear systems under directed graph

ABSTRACT This article addresses the distributed consensus problem of multi-agent systems with Lur'e nonlinear dynamics under directed graphs based on event-triggered strategy. With the state-dependent event-triggered thresholds, a novel distributed event-triggered consensus controller is designed, under which the consensus can be achieved with zero final consensus error. The proposed strategy has several distinguishing features, including the fact that individual agent does not require continuous, or even periodic, communication with their neighbours to update the controller or monitor the triggering condition, and all the required parameters can be locally determined by the agent. Furthermore, we also prove that there is no Zeno behaviour existed. Finally, the simulation example about Chua’s circuit is given to illustrate the theoretical analysis.
Observing relationships between sediment-laden meltwater plumes, glacial runoff and a retreating terminus at Blomstrandbreen, Svalbard

ABSTRACT Sediment-laden meltwater plumes are a common occurrence at the margins of marine-terminating glaciers in Svalbard and are useful proxies for inferring the glacial hydrological system and meltwater runoff. Plumes can influence calving rates, marine biogeochemistry and fjord circulation. However, little is known about how their dynamics will evolve in a warmer, wetter Arctic with increasing melt rates and retreating glacier margins. To determine the temporal magnitude and frequency evolution of sediment-laden meltwater plumes, we manually delineated plume outlines in every available Sentinel-2 image at Blomstrandbreen, Kongsfjorden, Svalbard, between 2016 and 2021. While the frequency of plumes upwelling on the fjord surface remained stable in each melt season, their surface area increased significantly by almost an order of magnitude between the beginning and end of the study period, owing primarily to glacial runoff. This significant change was a result of several large plumes (>2 km2) mapped in 2020 and 2021. The rate of glacier terminus change throughout the study period has little-to-no influence on plume surface area. However, a notable event concerning the terminus retreating into an overdeepening between 2017 and 2018 may have impacted plume magnitude, allowing for larger plume migration across the calving front after 2018. Seasonal supraglacial lakes on Blomstrandbreen are found to be small in both area and volume which have limited influence on plumes surfacing between 2016-2021. Our findings suggest with increased runoff, plumes upwelling at the glacier terminus may increase in size, transporting greater volumes of sediment into the surrounding local marine environment. These changes could be exacerbated by projected increases in glacier mass loss and retreat expected to occur across Svalbard throughout this century and beyond, making the study of plumes and their impacts key to constraining the transport of water and sediment from a terrestrial to a marine environment as demonstrated at Blomstrandbreen.
Enzymatic Characterization of the Isocitrate Dehydrogenase with Dual Coenzyme Specificity from the Marine Bacterium Umbonibacter marinipuiceus

Isocitrate dehydrogenase (IDH) can be divided into NAD+-dependent and NADP+-dependent types based on the coenzyme specificity. It is worth noting that some IDHs exhibit dual coenzyme specificity characteristics. Herein, a dual coenzyme-dependent IDH from Umbonibacter Marinipuiceus (UmIDH) was expressed, purified, and identified in detail for the first time. SDS-PAGE and Gel filtration chromatography analyses showed that UmIDH is an 84.7 kDa homodimer in solution. The Km values for NAD+ and NADP+ are 1800.0 ± 64.4 μM and 1167.7 ± 113.0 μM in the presence of Mn2+, respectively. Meanwhile, the catalytic efficiency (kcat/Km) of UmIDH is only 2.3-fold greater for NADP+ than NAD+. The maximal activity for UmIDH occurred at pH 8.5 (with Mn2+) or pH 8.7 (with Mg2+) and at 35 °C (with Mn2+ or Mg2+). Heat inactivation assay revealed that UmIDH sustained 50% of maximal activity after incubation at 57 °C for 20 min with either Mn2+ or Mg2+. Moreover, three putative core coenzyme binding residues (R345, L346, and V352) of UmIDH were evaluated by site-directed mutagenesis. This recent work identified a unique dual coenzyme-dependent IDH and achieved the groundbreaking bidirectional modification of this specific IDH’s coenzyme dependence for the first time. This provides not only a reference for the study of dual coenzyme-dependent IDH, but also a basis for the investigation of the coenzyme-specific evolutionary mechanisms of IDH.
The mediating effect of allostatic load on the association between life course socioeconomic disadvantage and chronic pain: a prospective finding from the National Survey of Midlife Development in the United States

Background Socioeconomic disadvantages (SEDs) are associated with chronic pain (CP) and allostatic load (AL). Few prospective population-based studies have examined the relationship between life course SED, CP interference, and CP widespreadness, and there is no prospective population-based study on whether AL mediates the association between SED and CP. Objective In this study, we investigated whether the prospective effect of SED on CP at Midlife in the United States (MIDUS) 3 is consistent with the accumulation of risk model and social mobility model, using the National Survey of MIDUS (n = 593). To prepare for the mediation analysis, we tested (1) whether SED would be prospectively associated with AL in the MIDUS 2 biomarker project, (2) whether AL would be prospectively associated with CP, and (3) whether childhood, as a critical period, moderated the association between AL and CP. In addition, the mediating effect of AL on the association between SED and CP was examined. Method SED was measured using cumulative scores and disadvantage trajectories derived from latent class trajectory modeling (LCTM). After multiple imputations, analyses were conducted using multinomial logistic regression for CP and negative binomial regression for AL, respectively. Finally, mediation analyses and moderated mediation analyses were performed. Results LCTM identified three SED trajectories, namely, constant low, high to low, and medium to high. The results showed that proximal cumulative SED was associated with high-interference CP. Furthermore, compared with the group with constant low SED, the group with medium-to-high SED was significantly associated with high-interference pain and experienced pain in at least three different sites. Cumulative SED and deteriorating SED trajectories were associated with higher AL, consistent with previous studies. Furthermore, childhood SED moderated the effect of AL on CP widespreadness and unexpectedly demonstrated a protective effect, while other associations between AL and CP were not significant. Subsequent mediation analysis did not yield statistically significant evidence. Conclusions People who experienced more recent SED or increasing disadvantage throughout their lives were more likely to suffer from CP, and this association was not mediated by physiological system dysregulation caused by chronic stress. Therefore, measures to alleviate AL may not be effective in protecting socioeconomically disadvantaged populations from CP.
Fourth Day of Creation: The Proto-history of Young Stars, Star Streams, and Exoplanets Near the Sun

Abstract Items of scientific knowledge at any moment in time have pre-histories when they were debated, doubted, or absolutely denied. The examples considered here are the admitted facts that star formation is an on-going process in the Milky Way, that there are young moving groups (the products of young star clusters in the process of dissolution and perhaps more complex processes), and that planets orbiting other stars are common. It is hard to imagine any of these ceasing to be part of core astronomical knowledge, but you are advised not to place large bets on this.
A Deep Learning-Based Hyperspectral Object Classification Approach via Imbalanced Training Samples Handling

Object classification in hyperspectral images involves accurately categorizing objects based on their spectral characteristics. However, the high dimensionality of hyperspectral data and class imbalance pose significant challenges to object classification performance. To address these challenges, we propose a framework that incorporates dimensionality reduction and re-sampling as preprocessing steps for a deep learning model. Our framework employs a novel subgroup-based dimensionality reduction technique to extract and select the most informative features with minimal redundancy. Additionally, the data are resampled to achieve class balance across all categories. The reduced and balanced data are then processed through a hybrid CNN model, which combines a 3D learning block and a 2D learning block to extract spectral–spatial features and achieve satisfactory classification accuracy. By adopting this hybrid approach, we simplify the model while improving performance in the presence of noise and limited sample size. We evaluated our proposed model on the Salinas scene, Pavia University, and Kennedy Space Center benchmark hyperspectral datasets, comparing it to state-of-the-art methods. Our object classification technique achieves highly promising results, with overall accuracies of 99.98%, 99.94%, and 99.46% on the three datasets, respectively. This proposed approach offers a compelling solution to overcome the challenges of high dimensionality and class imbalance in hyperspectral object classification.
Digital business agility

In the business environment, a high level of competitiveness is largely determined by technological development, hence the need for continuous adaptation of organizational strategies, often by digitally transforming the business models. Business agility, as the ability to identify and adapt to digital technologies in a timely manner, represents a successful response and plays a profound role in the organization's success. By analyzing recent literature, this paper examines the importance of digital business agility and how digital technologies themselves contribute to the development of comprehensive business agility. The paper describes the results of the research, which can serve as a strategic orientation for organizations on their journey to digital transformation and improved business agility
Electric Spark Discharges in Water. Low-energy Nuclear Transmutations and Light Leptonic Magnetic Monopoles in an Extended Standard Model

Abstract Light leptonic magnetic monopoles were predicted by Lochak [G. Lochak, Intern. J. Theor. Phys. 24, 1019 (1985). ]. Experimental indications based on nuclear transmutations were announced by Urutskoiev et al. [L. I. Urutskoiev, V. I. Liksonov, V. G. Tsinoev, Ann. Fond. L. de Broglie 27, Nr.4, 791 (2002). ] and Urutskoev [L. J. Urutskoev, Ann. Fond. L. de Broglie 29, 1149 (2004). ]. A theoretical interpretation of these transmutations is proposed under the assumption that light leptonic magnetic monopoles are created during spark discharges in water. The latter should be excited neutrinos according to Lochak. This hypothesis enforces the introduction of an extended Standard Model described in previous papers. The most important results of this study are (i) that multiple proton captures are responsible for the variety of transmutations and that leptonic magnetic monopoles are involved in these processes (ii) that electromagnetic duality can be established for bound states of leptonic monopoles although massive monopoles are in general unstable (iii) that criteria for the emission of leptonic magnetic monopoles and for their catalytic effect on weak decays are set up and elaborated. The study can be considered as a contribution to the efforts of Urutskoiev and Lochak to understand the reasons for accidents in power plants.
Pathogenicity of Trichoderma afroharzianum in Cereal Crops

Species of the genus Trichoderma occur ubiquitously in soils, on plant roots and in decaying plant residues. Due to its competitiveness and mycoparasitic potential against other microorganisms, particular strains of Trichoderma spp. are used in agriculture as biocontrol agents against plant pathogens. However, Trichoderma afroharzianum has been recently reported as a pathogen causing ear rot disease on maize in Germany, France and Italy, leading to massive infections on maize cobs. This raised the question, whether and to what extent Trichoderma spp. can infect cereal crops other than maize and cause disease symptoms and yield losses. To address this question, two varieties of wheat, barley and sorghum were grown in the greenhouse and artificially inoculated with T. afroharzianum by both spray and point inoculation at the time of flowering. Disease severity was scored weekly, and thousand-kernel weight and colonization rate were determined after harvest. As early as 14 days after inoculation, the first visual symptoms appeared on wheat and barley as tan or brown discoloration of the base of a floret within the spikelets. After spray inoculation, clear discolorations of the entire ear were seen, while point inoculation only showed symptoms at the injection site and above. No visible symptoms were observed on sorghum millet. The colonization rate on wheat and barley grains was significantly increased compared to the control, while thousand-kernel weights (TKWs) were significantly reduced. No differences in colonization rate and TKW compared to the control were observed in sorghum. This is the first report of Trichoderma afroharzianum infecting wheat and barley, causing disease symptoms and significantly reducing thousand-kernel weights.
The hybrid bio-robotic swarm as a powerful tool for collective motion research: a perspective

Swarming or collective motion is ubiquitous in natural systems, and instrumental in many technological applications. Accordingly, research interest in this phenomenon is crossing discipline boundaries. A common major question is that of the intricate interactions between the individual, the group, and the environment. There are, however, major gaps in our understanding of swarming systems, very often due to the theoretical difficulty of relating embodied properties to the physical agents—individual animals or robots. Recently, there has been much progress in exploiting the complementary nature of the two disciplines: biology and robotics. This, unfortunately, is still uncommon in swarm research. Specifically, there are very few examples of joint research programs that investigate multiple biological and synthetic agents concomitantly. Here we present a novel research tool, enabling a unique, tightly integrated, bio-inspired, and robot-assisted study of major questions in swarm collective motion. Utilizing a quintessential model of collective behavior—locust nymphs and our recently developed Nymbots (locust-inspired robots)—we focus on fundamental questions and gaps in the scientific understanding of swarms, providing novel interdisciplinary insights and sharing ideas disciplines. The Nymbot-Locust bio-hybrid swarm enables the investigation of biology hypotheses that would be otherwise difficult, or even impossible to test, and to discover technological insights that might otherwise remain hidden from view.
Modified active disturbance rejection control for non-linear semi-active vehicle suspension with magneto-rheological damper

This paper presents a novel idea processing the complex non-linear dynamics of a magneto-rheological (MR) damper and the external road disturbance based on the linear extended state observer (LESO) technology, and further verifies its reasonability by application of linear active disturbance rejection control (LADRC) in the quarter-car non-linear semi-active suspension system. In order to optimize the body acceleration and dynamic tyre load to improve the ride comfort and road-handling ability, a modified active disturbance rejection control, the double linear active disturbance rejection control (DLADRC), is further proposed based on the idea of the hybrid skyhook–groundhook control strategy. LESO is used to estimate the total disturbance including the external road disturbance and the internal non-linear dynamic of the MR damper. For effectiveness validation of the proposed control scheme, comparison results with the existing linear quadratic regulation (LQR) control, hybrid skyhook–groundhook control and adaptive control strategies are presented for the same quarter-car semi-active suspension. It is shown from the simulation comparisons among these several control strategies that the semi-active suspension system with DLADRC has a better control performance on the ride comfort and road-handling ability corresponding to the body acceleration and dynamic tyre load.
The Strengths and Weaknesses of Online Learning from The Perspectives of Teachers and Students in Sma/Smk Negeri Buleleng Sub-District During the Covid-19 Pandemic

This research aimed to analyse the strengths and weaknesses of online learning from the perspectives of teachers and students during the COVID-19 pandemic. The subjects of this research were English teachers and students in SMA/SMK Negeri in Buleleng sub-district. In this case, the subjects of the study consist of 21 English teachers including 11 male and 10 female teachers, and 42 students covering 20 male and 22 female students. The data of this research were obtained by using questionnaires. This research is descriptive qualitative research design. The result of this research found that the online learning has strengths and weaknesses according to the perceptions of the teachers and the students.