bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of heteroaggregation between microplastics and algae on particle vertical transport
Authors: Parrella Francesco , Brizzolara Stefano , Holzner Markus , Mitrano Denise M. 
Published: June 2024

AbstractUnderstanding the impacts of microplastics (MPs) on aqueous environments requires understanding their transport dynamics and how their presence affects other natural processes and cycles. In this context, one aspect to consider is how MPs interact with freshwater snow (FWS), a mixture of algae and natural particles. FWS is one of the primary drivers of the flux of organic matter from the water surface to the bottom sediment, where zooplankton, diurnal migration, fish faecal pellets settling and turbulent mixing can also play prominent roles. Understanding how MPs and FWS heteroaggregation affects their respective settling velocities is important to assess not only MPs fate and transport but also their ecological impacts by altering FWS deposition and thereby nutrient cycling. In this present study, we obtained a mechanistic understanding of the processes controlling MPs settling dynamics and heteroaggregation with FWS and the subsequent impacts on the settling rates of both MPs and ballasted FWS. Here we used a plexiglass column equipped with a stereoscopic camera system to track the settling velocities of (1) MPs of various compositions, densities and morphologies, (2) FWS flocs and (3) MP–FWS agglomerates. For each experimental set, thousands of particles were tracked over a series of image sequences. We found that agglomerates with high-density MPs settled at least twofold faster than FWS alone, implying a much smaller residence time in the water column, except for cases with MP fibres or low-density plastics. These findings will help to refine MP fate models and, while contingent on MPs number, may impact biogeochemical cycles by changing the flux of nutrients contained in FWS to the sediment.
Design, synthesis, and biological evaluation of multiple F-18 S1PR1 radiotracers in rodent and nonhuman primate
Authors: Qiu Lin , Jiang Hao , Zhou Charles , Tangadanchu Vijai Kumar Reddy , Wang Jinzhi , Huang Tianyu , Gropler Robert J. , Perlmutter Joel S. , Benzinger Tammie L. S. , Tu Zhude 
Published: June 2024

We synthesized and screened 28 new fluorine-containing S1PR1 compounds; 9 potent and selective compounds were F-18 radiolabeled with good radiochemical yields. In vivo PET imaging evaluation was performed for these radiotracers as CNS imaging agents.
Timing and scintillation studies of PSR J1439−5501
Authors: Jang J. , Main R. , Venkatraman Krishnan V. , Bailes M. , Cameron A. , Champion D. J. , Freire P. C. C. , Parthasarathy A. , Buchner S. , Kramer M. 
Published: June 2024

Context. PSR J1439−5501 is a mildly recycled pulsar in a 2.12-day circular orbit around a heavy white dwarf. A white dwarf cooling model has estimated the companion mass to be between 1 and 1.3 M⊙ and the inclination angle to be greater than 55°. Such high mass and inclination are expected to induce a Shapiro delay, namely, a relativistic time delay in the signal propagation caused by the curved space-time induced by the companion. Until now, however, no Shapiro delay has been measured in this system.
Aims. Our aim is to detect the Shapiro delay and, thus, to independently measure the mass and inclination of PSR J1439−5501 by using data from the Parkes and MeerKAT radio telescopes.
Methods. The Shapiro delay parameters were measured through pulsar timing, which coherently accounts for every rotation of the pulsar. These measurements were then used to estimate the masses of the component stars and the inclination angle of the binary. A scintillation analysis was additionally performed by investigating the secondary spectra, which are the Fourier-transformed observed scintillation patterns. The obtained secondary spectral variations were analyzed in terms of the orbital motion and annual variation to estimate the ascending nodes, distance, and the location of the screen.
Results. We obtained a highly significant measurement of the Shapiro delay, which allows estimates of the pulsar mass (1.57−0.26+0.30 M⊙), the white dwarf (WD) companion mass (1.27−0.12+0.13 M⊙), and inclination angle, (75(1)° or 105(1)°). These estimates assume that the companion mass cannot exceed the Chandrasekhar mass limit (1.48 M⊙), along with a lower limit of 1.17 M⊙ for NS masses. These results are consistent with previous studies, but the precision of the component masses has been improved significantly. The orbital and spin parameters and the large WD mass make this system very similar to that of PSR J2222−0137 and PSR J1528−3146, thereby suggesting a common evolutionary mechanism. The scintillation analysis suggests that the longitude of the ascending node is 16(7)° or −20(6)°, depending on the sense of the inclination angle. The screen distance is 260 ± 100 pc, potentially associated with the edge of the Local Bubble.
Investigating and comparing the IRIS spectral lines Mg II, Si IV, and C II for flare precursor diagnostics
Authors: Zbinden Jonas , Kleint Lucia , Panos Brandon 
Published: June 2024

Context. Reliably predicting solar flares can mitigate the risks of technological damage and enhance scientific output by providing reliable pointings for observational campaigns. Flare precursors in the spectral line Mg II have been identified.
Aims. We extend previous studies by examining the presence of flare precursors in additional spectral lines, such as Si IV and C II, over longer time windows, and for more observations.
Methods. We trained neural networks and XGBoost decision trees to distinguish spectra observed from active regions that lead to a flare and those that did not. To enhance the information within each observation, we tested different masking methods to preprocess the data.
Results. We find average classification true skill statistics (TSS) scores of 0.53 for Mg II, 0.44 for Si IV, and 0.42 for C II. We speculate that Mg II h&k performs best because it samples the highest formation height range, and is sensitive to heating and density changes in the mid- to upper chromosphere. The flaring area relative to the field of view has a large effect on the model classification score and needs to be accounted for. Combining spectral lines has proven difficult, due to the difference in areas of high probability for an imminent flare between different lines.
Conclusions. Our models extract information from all three lines, independent of observational bias or GOES X-ray flux precursors, implying that the physics encoded in a combination of high resolution spectral data could be useful for flare forecasting.
Infrared emissivity of icy surfaces
Authors: Ferrari C. 
Published: June 2024

Context. Most analyses of the infrared emission of Saturn’s rings and icy satellites have considered pure water ice as the constituent of regolith and particle surfaces. Visual and near-infrared observations have shown, however, that darkening and reddening contaminants are present at a fraction level of a few percent. In the spectral domain 10–2000 cm−1, water ice becomes transparent in a few windows, which in particular causes the roll-off of emissivity of icy surfaces that is observed below 50 cm−1. Their emissivity there may be affected by these contaminants.
Aims. We present a quantitative global sensitivity analysis of a hybrid Mie-Hapke model to evaluate the influence of regolith properties and contaminant fraction on the infrared emissivity of icy rings or moons over this spectral range.
Methods. A hybrid Mie–Hapke model of the hemispherical emissivity ε*h(Wn) was made, including various diffraction correction and mixing types with tholins or amorphous carbon grains, or grain size distributions and some anisotropy in emission. A Sobol global sensitivity analysis provided quantitative levels of importance for these factors versus wave number wn.
Results. Given the a priori uncertainties, the most important factor acting on ε*h(Wn) remains the size distribution of regolith grains and the average anisotropy factor ξ. For wn> 50 cm−1, ξ, the power-law index p and the minimum amin of the size distribution are most influential. In windows of water-ice transparency (10–50, 300–600, and 900–1300 cm−1), the emissivity is also sensitive, but to a lesser extent, to the maximum grain size amax and the fraction f of contaminants, if mixed at the molecular level.
Conclusions. This model provides a self-consistent tool for interpreting multi-modal observations of the thermal emission from icy surfaces. It also offers interesting insights into recent mid-infrared observations of Saturn’s rings and Jupiter’s moon Ganymede by the JWST-MIRI instrument.
Correcting Fabry-Pérot etalon effects in solar observations
Authors: Santamarina Guerrero P. , Orozco Suárez D. , Bailén F. J. , Blanco Rodríguez J. 
Published: June 2024

Context. Data processing pipelines of Fabry–Pérot interferometers (FPI) must take into account the side effects these devices introduce in the observations. Interpretation of these observations without proper correction can lead to inaccurate or false results, with consequent impact on their physical interpretation. Corrections typically require prior knowledge of the properties of the etalon and the way they affect the incoming light in order to calibrate the data successfully.
Aims. We have developed an algorithm to derive etalon properties from flat-field observations and tested its applicability and accuracy using simulated observations and real measurements.
Methods. We employed analytical expressions of the transmission profiles for FPIs in collimated and telecentric configurations to derive their expected impact on the observations. These analytical expressions allowed us to develop a customized optimization algorithm capable of inferring the properties of the etalon from the observations. The algorithm’s performance has been tested on simulated observations with an etalon in collimated and telecentric setups employing various noise levels and spectral samplings. Additionally, we explored how tilting the etalon in a telecentric configuration influences the algorithm’s effectiveness. Lastly, we also applied the algorithm to a set of real flat-field observations taken with the high-resolution telescope of the Polarimetric and Helioseismic Imager on board the Solar Orbiter mission (HRT-SO/PHI).
Results. The algorithm is able to retrieve the gain and etalon induced transmission velocity shifts (cavity map), with an average accuracy ranging between 0.4% and 0.1% for the former and between 120 m s−1 and 30 m s−1 for the latter. Both reducing the noise level and increasing the spectral sampling of the observations proved to greatly increase the algorithm’s performance, as expected. Results also suggest that determination of the observed object from the data is possible but an additional error between 40 m s−1 and 10 m s−1 is to be expected in the inferred cavity map. Furthermore, we show that neglecting the asymmetries arising from either tilts of the etalon or imperfections in the telecentrism can lead to large errors when determining the gain. Tests with HRT-SO/PHI data have verified the applicability of the algorithm in real cases.
Conclusions. Our presented method enabled us to derive the transmission profile of FPIs from observations of collimated and telecentric configurations. It has proven to be robust against the presence of noise and limited spectral line sampling. The results reported here also show the importance of accounting for the asymmetries arising in real telecentric mounts when interpreting the results of real instruments.
Chemical abundances along the quasar main sequence
Authors: Floris A. , Marziani P. , Panda S. , Sniegowska M. , D’Onofrio M. , Deconto-Machado A. , del Olmo A. , Czerny B. 
Published: June 2024

Context. The main sequence of quasars has emerged as a powerful tool for organizing the observational and physical characteristics of type-1 active galactic nuclei (AGNs).
Aims. In this study, we present a comprehensive analysis of the metallicity of the gas in the broad-line region, incorporating both new data and previously published findings, to assess the presence of any trend along the main sequence.
Methods. We performed a multicomponent analysis on the strongest ultraviolet (UV) and optical emission lines for a sample of 13 radio quiet quasars in the 0.009 ≤ z ≤ 0.472 redshift range, selected based on the availability of multiwavelength data. We employed UV and optical data obtained from the Hubble Space Telescope (mainly from the Cosmic Origins Spectrograph and Faint Object Spectrograph) and several ground-based observatories, respectively. We then measured ten diagnostic ratios and compared them with the prediction of CLOUDY photoionization simulations, identifying the closest photoionization solution to the data.
Results. Our investigation reveals a consistent pattern along the main sequence. We observe a systematic progression in metallicity, ranging from subsolar values to metallicity levels several times higher than solar values.
Conclusions. These findings underscore the fundamental role of metallicity in correlating with the main sequence of quasars. Extreme metallicity values, at least several dozen times the solar metallicity, are confirmed in low-z AGNs radiating at a high Eddington ratio, although the origin of the extreme enrichment remains open to debate.
The impact of educational digitalization on the creativity of students with special needs: the role of study crafting and creative self-efficacy
Authors: Zhang Qi , Shi Boxuan , Liu Yuchao , Liang Zhou , Qi Liangqun 
Published: June 2024

AbstractSpecial needs are of paramount importance in international equitable education. The focus on students with special needs has become the basis of current special education and education reform. The world is currently undergoing a pivotal phase of digital transformation, with educational digitalization gradually developing. However, only a few studies have focused on the effect of educational digitalization on the creativity of students with special needs, and most of them have ignored its internal mechanism. This study therefore aims to explore the manner in which and the circumstances under which educational digitalization affects the creativity of students with special needs. Building upon information theory, this study proposes a mediated moderating framework to examine the effects of educational digitalization on the creativity of students with special needs, considering the mediating role of studying crafting and the moderating effect of creative self-efficacy. A survey methodology was employed to collect empirical data on the interrelationships among educational digitalization, study crafting, creative self-efficacy, and the creativity of students with special needs. The results demonstrated a significant positive relationship between educational digitalization and the creativity of students with special needs through study crafting. Furthermore, creative self-efficacy was found to play a moderating role in this process. The findings provide educators and policymakers with practical guidance on how to optimize the implementation of digital technologies in educational environments in order to promote education equity.
Quantum information splitting among N-quantum nodes within a quantum network by using Bell states
Authors: Verma Vikram 
Published: June 2024

Abstract
In quantum information processing, it is essential to ensure the security of quantum information so that it cannot be stolen and interrupted by an eavesdropper. For ensuring the security of information, quantum information splitting (QIS) method is used in which quantum communication is made more secure by splitting the quantum information among the various quantum nodes within a quantum network in such a way that any one node can retrieve the quantum information completely with the collaboration of remaining quantum nodes. In this paper, by using Bell states as the quantum channel we present a simple and precise scheme for quantum information splitting of an arbitrary single-qubit quantum information state among N (N ≥ 2) recipient nodes which are separately entangled with the sender node only and not with one another. We also generalize our scheme to the splitting of multi-qubit quantum information state among the N recipient nodes by using 2-qubit Bell states as the quantum resource. In comparison to the previous existing QIS schemes which require multi-qubit entangled states as the quantum resource, our proposed QIS scheme is very simple and feasible.
Investigating the properties of co-precipitated nickel cobalt phosphate (NiCoP) nanoparticles for energy storage applications
Authors: Alshoaibi Adil , Nkele Agnes C , Getaneh Seyoum A , Awada Chawki , Islam Shumaila , Ezema Fabian I 
Published: June 2024

Abstract
Nickel cobalt phosphate (NiCoP) nanoparticles were synthesized by a co-precipitation method at concentrations of 0.1 M, 0.2 M, 0.3 M, 0.4 M, and 0.5 M. Drop-casting method was utilized in depositing the nanoparticles on the substrate surface to ensure uniform distribution on the substrate surface. Various analytical techniques including XRD, SEM, EDX, Raman spectroscopy, and electrochemical measurements were employed to comprehensively understand the structural, morphological, elemental, vibrational, and electrochemical properties of the synthesized nanoparticles. Results indicate amorphous phases for all samples, with nanoflake-like morphology observed via SEM, and constituent elements confirmed through EDX analysis. Raman spectroscopy validates the composition, while electrochemical measurements demonstrate the NiCoP electrodes’ promising utility in energy storage, particularly with the 0.1 M electrode exhibiting a maximum specific capacitance of 91.2 F g−1 and stability over 3000 cycles. Overall, the findings highlight the potential applications of NiCoP nanoparticles in energy storage and electrochemical devices, providing valuable insights for researchers in the field.
Holographic timelike entanglement entropy from Rindler method*
Authors: He 贺 Peng-Zhang 鹏璋 , Zhang 张 Hai-Qing 海青 
Published: June 2024

Abstract
For a Lorentzian invariant theory, the entanglement entropy should be a function of the domain of dependence of the subregion under consideration. More precisely, it should be a function of the domain of dependence and the appropriate cut-off. In this study, we refine the concept of cut-off to make it applicable to timelike regions and assume that the usual entanglement entropy formula also applies to timelike intervals. Using the Rindler method, the timelike entanglement entropy can be regarded as the thermal entropy of the CFT after the Rindler transformation plus a constant

, where c denotes the central charge. The gravitational dual of the 'covariant' timelike entanglement entropy is presented following this method.
Topology of charged AdS black hole in restricted phase space*
Authors: Wang 王 Han 菡 , Du 杜 Yun-Zhi 云芝 
Published: June 2024

Abstract
The local topological properties of black hole systems can be expressed through winding numbers as defects. To date, AdS black hole thermodynamics are often depicted by the dual parameters of

in the extended phase space, while there have been several studies on the black hole thermodynamics in the restricted phase space. In this paper, we analyze the topological properties of charged AdS black holes in the restricted phase space under the higher-dimension and higher-order curvature gravity frame. The results show that the topological number of the charged black hole in the same canonical ensembles is a constant and is independent of the concrete dual thermodynamical parameters. However, the topological number in the grand canonical ensemble is different from that in the canonical ensemble for the same black hole system. Furthermore, these results are independent of dimension d and highest order k of the Lanczos-Lovelock densities.
Flexures for Kibble balances: minimizing the effects of anelastic relaxation
Authors: Keck Lorenz , Schlamminger Stephan , Theska René , Seifert Frank , Haddad Darine 
Published: June 2024

Abstract
We studied the anelastic aftereffect of a flexure being used in a Kibble balance, where the flexure is subjected to a large excursion in velocity mode after which a high-precision force comparison is performed. We investigated the effect of a constant and a sinusoidal excursion on the force comparison. We explored theoretically and experimentally a simple erasing procedure, i.e. bending the flexure in the opposite direction for a given amplitude and time. We found that the erasing procedure reduced the time-dependent force by about 30%. The investigation was performed with an analytical model and verified experimentally with our new Kibble balance at the National Institute of Standards and Technology employing flexures made from precipitation-hardened Copper Beryllium alloy C17200. Our experimental determination of the modulus defect of the flexure yields

1.2
×

10

−
4

. This result is about a factor of two higher than previously reported from experiments. We additionally found a static shift of the flexure’s internal equilibrium after a change in the stress and strain state. These static shifts, although measurable, are small and deemed uncritical for our Kibble balance application at present. During this investigation, we discovered magic flexures that promise to have very little anelastic relaxation. In these magic flexures, the mechanism causing anelastic relaxation is compensated for by properly shaping and loading a flexure with a non-constant cross-section in the region of bending.
A simple and effective method for smartphone-based detection of polyamines in oral cancer
Authors: Mojumdar Asmita , B S Unnikrishnan , Packirisamy Gopinath 
Published: June 2024

Abstract
Oral cancer accounts for 50%–70% of all cancer-related deaths in India and ranks sixth among the most frequent cancers globally. Roughly 90% of oral malignancies are histologically arise from squamous cells and are therefore called oral squamous cell carcinoma. Organic polycations known as biogenic polyamines, for example, putrescine (Put), spermidine (Spd), and spermine (Spm), are vital for cell proliferation, including gene expression control, regulation of endonuclease-mediated fragmentation of DNA, and DNA damage inhibition. Higher Spm and Spd levels have been identified as cancer biomarkers for detecting tumour development in various cancers. The current study utilises tannic acid, a polyphenolic compound, as a reducing and capping agent to fabricate AuNPs via a one-step microwave-assisted synthesis. The fabricated TA@AuNPs were utilised as a nanoprobe for colourimetric sensing of polyamines in PBS. When TA@AuNPs are added to the polyamine, the amine groups in polyamines interact with the phenolic groups of TA@AuNPs via hydrogen bonding or electrostatic interactions. These interactions cause the aggregation of TA@AuNPs, resulting in a red shift of the Surface Plasmon Resonance band of TA@AuNPs from 530 nm to 560 nm. The nanoprobe was found to be highly specific for Spm at low concentrations. TA@AuNPs were able to detect Spm successfully in artificial saliva samples. On recording the RGB values of the sensing process using a smartphone app, it was found that as the nanoparticles aggregated due to the presence of Spm, the intensity of the R-value decreased, indicating the aggregation of TA@AuNPs due to interaction with the polyamine.