bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the predictability horizon in Impact Monitoring of Near Earth Objects
Authors: Tommei Giacomo , Valsecchi Giovanni B. 
Published: October 2024

AbstractThe Impact Monitoring (IM) of Near Earth Objects (NEOs) is a fundamental part of the planetary defense strategy. Current NEO IM systems (Aegis, NEODyS and Sentry) scan the Confidence Region (CR) of each observed object looking for Virtual Impactors (VIs) with a time horizon of about 100 years. This procedure is performed regardless of the uncertainty with which the orbit of the object is known, and without considering whether a scattering encounter is present in the propagation time span. In view of the likely future increase of the IM workload due to higher future NEO discovery rates, it might be more reasonable to adapt the predictability horizon of the impacts to each object, taking into account the orbit uncertainty and the close encounters experienced. In this paper we discuss the problem of estimating a reasonable predictability horizon when multiple close encounters are present and start to address the problem proposing a formal mathematical definition of scattering encounter.
On the computation of resonant tidal dissipation in the liquid layers of planets and stars
Authors: Rekier Jérémy , Triana Santiago A. 
Published: October 2024

AbstractPlanets and stars have liquid layers that can support internal gravity waves and inertial waves respectively restored by the buoyancy and Coriolis forces. Both types of waves are excited by tides, leading to resonantly amplified dissipation. We review the theoretical formalism to compute these resonances and present some challenges and methods to overcome them.
Secular Resonance Maps
Authors: Knežević Zoran 
Published: October 2024

AbstractA complete list of combinations of the rates of asteroid perihelia and nodes and the corresponding fundamental frequencies of planets, giving rise to secular resonances and involving up to 4 frequencies, is known from the previous work, while for the resonances with 6 frequencies a systematically derived comprehensive list is given here for the first time. There are 28 divisors in the theory of degree up to 4, not all of which can give rise to resonances, while at degree 6 there are (at least) 33 such possibly resonant frequency combinations.Mapping the secular resonances by plotting the resonant lines in the phase space of proper elements or of secular frequencies, possibly also against the background of known asteroids, enables to straightforwardly identify resonances causing large long periodic variations of asteroid orbital elements, resonances that interact with known families, those that bound the dynamically distinct regions, deplete or disturb asteroids in these regions, etc.
On the long-term orbital evolution of a satellite revolving around an oblate body
Authors: Nadabaică Gabriela-Ana 
Published: October 2024

AbstractIn the context of a perturbed two body problem, in which the Keplerian motion of the small object (the satellite) is perturbed by the oblateness of the central body (the asteroid) and the attraction of a third body (the Sun), we discuss the long-term evolution of the orbital elements of a satellite orbiting an oblate body, with a particular focus on the behavior of the inclination and the longitude of the ascending node. We derive analytically the position of the Laplace plane as a function of several parameters and use this solution to analyse the long-term evolution of distant circular orbits. The analytical study is complemented by numerical tests, performed in the context of both Cartesian and Hamiltonian frameworks. The results give a description of the orbital dynamical environment of asteroids and reveal the parameters that play a key role in the long-term stability of distant circular orbits.
Lagrangian descriptors and their applications to deterministic chaos
Authors: Daquin Jérôme 
Published: October 2024

AbstractWe present our recent contributions to the theory of Lagrangian descriptors for discriminating ordered and deterministic chaotic trajectories. The class of Lagrangian descriptors we are dealing with is based on the Euclidean length of the orbit over a finite time window. The framework is free of tangent vector dynamics and is valid for both discrete and continuous dynamical systems. We review its last advancements and touch on how it illuminated recently Dvorak’s quantities based on maximal extent of trajectories’ observables, as traditionally computed in planetary dynamics.
Deconvolving the complex structure of the asteroid belt
Authors: Dermott Stanley F. , Li Dan , Christou Apostolos A. 
Published: October 2024

AbstractThe asteroid belt is a unique source of information on some of the most important questions facing solar system science. These questions include the sizes, numbers, types and orbital distributions of the planetesimals that formed the planets, and the identification of those asteroids that are the sources of meteorites and near-Earth asteroids. Answering these questions requires an understanding of the dynamical evolution of the asteroid belt, but this evolution is governed by a complex interplay of mechanisms that include catastrophic disruption, orbital evolution driven by Yarkovsky radiation forces, and chaotic orbital evolution driven by gravitational forces. While the timescales of these loss mechanisms have been calculated using estimates of some critical parameters that include the thermal properties, strengths and mean densities of the asteroids, we argue here that the uncertainties in these parameters are so large that deconvolution of the structure of the asteroid belt must be guided primarily by observational constraints. We argue that observations of the inner asteroid belt indicate that the size-frequency distribution is not close to the equilibrium distribution postulated by Dohnanyi (1969). We also discuss the correlations observed between the sizes and the orbital elements of the asteroids. While some of these correlations are significant and informative, others are spurious and may arise from the limitations of the Hierarchical Clustering Method that is currently used to define family membership.
Progress report on the BEBOP search for circumbinary planets with radial velocities
Authors: Baycroft Thomas A. , Triaud Amaury H. M. J. , Lai Dong 
Published: October 2024

AbstractThe BEBOP (Binaries Escorted By Orbiting Planets) survey is a search for circumbinary planets using the radial velocity spectrographs HARPS and SOPHIE, currently focusing on single-lined binaries with a mass ratio < 0.3. Circumbinary systems are an important testing ground for planet formation theories as the dynamically complex influence of the binary makes planet formation and survival more difficult. Here we present the results of the survey so far including: confirmed planets such as BEBOP-1c the first circumbinary planet detected in radial velocity; the status of our observations; and preliminary occurrence rates. We compare the early results of the radial velocity survey to the population of circumbinary planets discovered in transit, and suggest that there may be a population of inflated planets close to the inner binary which are detectable in transit but more difficult in radial velocity. Using time-lag tidal theory, we show that this inflation is unlikely caused by tides.
Can the stellar dynamical tide destabilize the resonant chains of planets formed in the disk?
Authors: Kwok Leon Ka Wang , Bolmont Emeline , Revol Alexandre , Mathis Stéphane , Astoul Aurélie , Charbonnel Corinne , Raymond Sean 
Published: October 2024

AbstractEvolution models of planetary systems find that resonant chains of planets often arise from the formation within protoplanetary disks. However, the occurrence of observed resonant chains, such as the notable TRAPPIST-1 system, is relatively low. This suggests that the majority of these chains become destabilized after the dissipation of the protoplanetary disk. Stellar tides, especially the wavelike dynamical tide, could be proposed as potential contributors to the destabilization of resonant chains. The dissipation of the dynamical tide, because of the frequency-dependant tidal excitation of stellar oscillation eigenmodes, potentially leads to a boost in migration for the close-in planets and disrupts the fragile stability of resonant chains. Thus, we investigate the influence of the stellar dynamical tide on multi-planet systems with taking their dissipation into account in the N-body code Posidonius. Notably, this research represents the first exploration of the impact of frequency-dependent dynamical tides on multi-planet systems.
Stability maps for the 5/3 mean motion resonance between Ariel and Umbriel with inclination
Authors: Gomes Sérgio R. A. , Correia Alexandre C. M. 
Published: October 2024

AbstractThe evolution of the five largest satellites of Uranus during the crossing of the 5/3 mean motion resonance between Ariel and Umbriel is strongly affected by chaotic motion. Studies with numerical integrations of the equations of motion and analysis of Poincaré surface sections provided helpful insights to the role of chaos on the system. However, they lack of a quantification of this chaos in the phase-space. Here, we construct stability maps using the frequency analysis method. We determine that for low energies (small eccentricity and/or inclinations), the phase-space is mainly stable. As the energy increases, the chaotic regions replace the stable motion, until only small, localized libration regions remain stable.
Collision outcomes due to planetesimal and planetary embryo interactions in inclined binary star systems
Authors: Zimmermann Maximilian , Pilat-Lohinger Elke 
Published: October 2024

AbstractIn the final phase of terrestrial planet formation, planetary embryos and planetesimals are the building blocks for the growth of rocky planets. In this investigation, we study the dynamical behaviour of a circumstellar disk in an inclined binary star system. The disk consists of 2000 planetesimals and 25 embryos and is distributed between 1 and 4 au around the primary star. To compute the gravitational interaction of the whole system, we use our recently developed GPU N-body code GANBISS. GANBISS treats all collision as perfect merging and delivers the impact parameters that will be used to distinguish between different collision outcomes.
Long-term evolution of exoplanet systems
Authors: Petrovich Cristobal 
Published: October 2024

AbstractIn this Review, I discuss recent developments on the long-term dynamical evolution of exoplanet systems, focusing on how distinctive dynamical processes may have shaped the orbital architectures of observed populations. I include three applications that highlight part of my own work. First, I examine the high-eccentricity tidal migration of hot Jupiters from a phase of dynamical instability and subsequent secular interactions in two-planet systems. Second, secular chaos as the origin of ultra-short-period planets with extreme period ratios. Third, secular resonance sweeping driven by a dispersing protoplanetary disk as the origin hot Neptunes residing in polar orbits. Finally, I discuss how upcoming observations will allow further constraining the prevalence of these dynamical processes.
Sun-planets tidal interactions: an extended catalog
Authors: Kudryavtsev Sergey M. , Cionco Rodolfo G. , Soon Willie W.-H. 
Published: October 2024

AbstractAn extended catalog of long-periodic terms of the Sun tide-generating potential (STGP ver.2) is released. It contains 2.5 times of such terms than in the first version of the STGP catalog (Cionco et al. 2023). The analysis of the new data is done in order to re-examine the existence of tidal forces of ≈ 11.0-yr and ≈ 22.0-yr period able to excite the observed solar-activity cycles. In several recent studies, such tidal forcings are claimed to be a result of certain combinations of Venus, Earth and Jupiter mean motions with the multipliers (6, −10, 4) and (3, −5, 2), respectively. So, in this contribution, we specifically look for the periodic terms related to these combinations. As a result of these additional investigation we do not confirm any noticeable tidal forcing factors of ≈ 11.0-yr nor ≈ 22.0-yr period in the extended STGP spectrum either.
Tidal effects in resonant chains of close-in planets: TTV analysis of Kepler-80
Authors: Charalambous Carolina , Libert Anne-Sophie 
Published: October 2024

AbstractSystems near mean-motion resonances (MMRs) are subject to large transit-timing variations (TTVs). The amplitude and period of the TTVs strongly depend on the distance to exact MMR and the planetary eccentricities which are shaped during the formation and long-term evolution of the system. For close-in planets, the tides raised by the star provide a source of dissipation, placing the planets further away from the MMR. In this work, we will discuss how the tidal interactions with the central star play an important role in shaping the period ratios and resonant angles in resonant chains. Moreover, we will show how they can impact the TTVs and therefore how the TTVs could serve as a means to put constraints on the tidal history of planetary systems. The study will focus on the four-planet resonant chain of Kepler-80.
Looking to Livestock: Gauging the Evolution of the EU's Agri-Climate Law and Policy
Authors: Williams Rebecca 
Published: October 2024

Abstract
Awareness of agricultural climate impacts is growing. In the European Union (EU), the agricultural sector is responsible for significant greenhouse gas emissions while continuing to receive considerable EU budgetary support. A large share of agricultural emissions is linked to livestock husbandry, a sector the direct and indirect climate impacts of which the EU's ‘green’ agricultural policies have historically ignored. This blind spot extends to the sizeable global deforestation footprint from EU livestock feed imports that remains unaddressed, despite the EU's aspired status as a global climate leader and major global agricultural market player. This article benchmarks the evolution of EU agri-climate legal and policy developments, using livestock emissions as a case study to highlight the importance of learning from the successes and failures of the EU experience, to realize future attempts to tackle global agricultural emissions.
Upwind Moisture Controls on Interannual Variations of Precipitation and Vegetation in China's Drylands
Authors: Li Yan , Xu Ru , Yang Zhao , Zhou Sha , Lu Mengqian , Lin Huiqing , Zi Shuangshuang , Su Ruijie 
Published: October 2024

AbstractDryland precipitation depends on upwind and local moisture sources via moisture recycling. How upwind moisture variations affect interannual variations of downwind precipitation and vegetation in China's drylands remains unclear. We used high‐resolution moisture tracking data sets and found terrestrial moisture (93%) was the dominant moisture source for China's drylands, especially from drylands themselves (46%). In most dryland grids, we observed strong correlations between precipitation and upwind moisture sources from 2003 to 2022 (median r = 0.55), with a more significant effect in drier areas. These demonstrated the upwind moisture control on interannual variations of dryland precipitation, in which internal moisture from drylands exceeds the influence of external terrestrial sources. The upwind moisture variations, especially the recycled moisture of drylands, propagate to influence downwind vegetation greenness in precipitation‐sensitive dryland areas. Our findings revealed that upwind moisture variations induced by climate or land‐cover changes have important implications for water and food security in China's drylands.
Mg Exosphere of Mercury Observed by PHEBUS Onboard BepiColombo During Its Second and Third Swing‐Bys
Authors: Suzuki Y. , Quémerais E. , Chaufray J.‐Y. , Robidel R. , Murakami G. , Leblanc F. , Yoshioka K. , Yoshikawa I. , Korablev O. 
Published: October 2024

AbstractMercury's exosphere is an important target for understanding the dynamics of coupled systems in space environments, tenuous planetary atmospheres, and planetary surfaces. Magnesium (Mg) is especially crucial for establishing methods for estimating the surface chemical composition distribution through observations of the exosphere because its distribution in the exosphere and on the surface is strongly correlated. However, owing to its low radiance, the Hermean Mg exosphere has only been detected by the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) onboard the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) spacecraft. Thus, we have few observation data for areas other than low latitude regions in addition to few detection cases of short‐term or sporadic fluctuations, resulting in a poor understanding of ejection and transportation mechanisms of the Mg exosphere. In this study, we analyzed the distribution of the Hermean Mg exosphere by the Probing of Hermean Exosphere by Ultraviolet Spectroscopy (PHEBUS) onboard the Mercury Planetary Orbiter of the BepiColombo mission during its second and third Mercury swing‐bys (MSBs). First, we constructed a calibration method including background subtraction and calibration using stellar observations. Mg light curves at two true anomaly angles were obtained, which were in agreement with the Chamberlain model and a three‐dimensional numerical calculation. Comparing the Mg and calcium (Ca) radiances obtained by PHEBUS during the MSBs, the exospheric Mg atoms have a lower energy than the exospheric Ca atoms. This is consistent with the lower energy necessary for producing the Mg atoms produced by molecular photodissociation than for Ca atoms.
Mechanical performance and dimensional stability of Washingtonia/Kenaf fibres-based epoxy hybrid composites
Authors: Saba Naheed , Awad Sameer A. , Jawaid M. , Hashem Mohamed , Fouad Hassan , Uddin Imran , Singh Balbir 
Published: October 2024

AbstractIn this study, Washingtonia fibres (AW) and Kenaf fibres (KF) were utilized as environmentally friendly fillers to improve the quality of the resin matrix. The mechanical, morphological, and physical properties of the WA/KF biocomposites were assessed throughout this research. The mechanical tests (tensile strength and moduli, elongation at break, flexural strength along with moduli, and the impact properties) were carried out. The hybrid biocomposites (3AW/7KF) exhibited the highest tensile strength (16.05 MPa) and modulus (4.6 GPa) among pure and other hybrid biocomposites. The impact strength and resistance of hybrid biocomposites (1AW/1KF and 7AW/3KF) showed the highest impact strength (1694 J/m2) while the 3AW/7KF hybrid biocomposite, the impact strength value was 1630 J/m2 (17.2 J/m). SEM images indicated good distribution and bonding of hybrid biocomposites. The investigation using morphological tests (Scanning Electron Microscopy (SEM)) displays the longitudinal roughness on the surface, which acts as a very significant function in the adhesion between the AW/KF fibres and the resin. Furthermore, the results of SEM confirm better bonding in the biocomposites, fibre fracture, pull-out, fibre shearing, and tearing in the pure and hybrid composites. From the water absorption test, it was observed that, when increasing the immersion time of biocomposites, the WA percentage of KF biocomposite significantly increased (37%) compared to other biocomposites. However, the hybrid and pure biocomposites exhibited more resistance to increase the WA percentage after increasing the immersion times, compared to other biocomposites. Furthermore, the thickness swelling (TS) of hybrid biocomposites increased compared to pure biocomposites. The biocomposite sample (3AW/7KF) was thicker on the 7th day exhibiting the greatest increases in thickness swelling (4.98%) while the hybrid biocomposite exhibited greater WA value compared to other correspondence samples. Finally, the KF and AW hybrid blends can be appropriate for several applications, for example, textiles, machinery part production industries, medicine, and automobiles, and construction, specifically buildings, bridges, and structures such as boat hulls, swimming pool panels, racing car bodies, shower stalls, bathtubs, storage tanks. Overall, the findings exhibit that the hybridisation of natural fibres (KF/AW) is a sustainable approach for obtaining biocomposites with advanced mechanical and thermal performance. Hence, they could be used in numerous specific applications, including automobile panels, structural products, sporting goods and furniture tools.
Production and characterization of pulp and paper from flax straw
Authors: Hailemariam Tsiye Tekleyohanis , Woldeyes Belay 
Published: October 2024

AbstractFlax (Linum usitatissimum) is a bast fiber plant known for its long fibers, making it an excellent source of pulp for paper production. In Ethiopia, flax is primarily cultivated for oil, with the residual straw utilized for papermaking. This study focuses on pulping flax straw using the Kraft process and investigates its chemical composition, proximate analysis, and morphological properties. The proximate analysis revealed an ash content of 4.13% and moisture content of 11%. Chemical composition analysis showed cellulose at 51.34%, hemicellulose at 25.20%, lignin at 14.12%, ash at 4.13%, and extractives at 5.21%. The morphological properties included a fiber length of 1.41 mm, diameter of 16.78 μm, lumen width of 9.45 μm, and cell wall thickness of 3.77 μm. Flax straw exhibited an acceptable Runkel ratio (0.8) and flexibility coefficient (56.32), placing it within the range of non-wood fibers. SEM analysis of the pulp’s morphology was conducted to assess fiber structure, including the presence of cracks. Pulp quality and length are directly linked to paper strength. Various pulping conditions were studied using a full-factorial design, with optimum conditions being 10% alkaline, 131.74°C, and 120 min of cooking time, yielding a pulp with a Kappa number of 10.45 and a yield of 40.56%. The resulting paper demonstrated standard tensile, tearing, and burst strengths, indicating that flax straw is a promising raw material for paper production.
Research on time characteristic sea surface temperature prediction based on decomposition
Authors: Chen Jing , Xu Wentao , Jiang Hongbin , Chen Xiao 
Published: October 2024

Abstract
The effective prediction of sea surface temperature has become a hot topic of scientific research. The hidden characteristics and time characteristics of sea surface temperature are studied, and a new sea surface temperature prediction model SLA based on decomposition is proposed in this paper. Firstly, the trend term and periodic seasonal term of sea surface temperature were decomposed by STL decomposition algorithm, which improved the problem of single characteristics of sea surface. Secondly, on the basis of the calculation method of the improved LSTM model and the attention mechanism, the problem that the prediction of sea surface temperature cannot be remembered in the long term and the influence weight of historical information is ignored is solved. Finally, the sea surface temperature of the South China Sea (112.125E,10.125N) was taken as the research object, and the experimental verification was carried out in three data sets. The experimental results show that the SLA model proposed in this paper has good prediction accuracy.
Solving inverse boundary value problem of Poisson equation by LS-SVM
Authors: Huang Minghao , Wu Ziku , Han Xiaoming 
Published: October 2024

Abstract
In this paper, a new method based on least squares support vector machines (LS-SVM) is presented for solving the inverse boundary value problem of Poisson equation. The closed form analytical solution is obtained by optimizing the regression parameters. The core problem is to transform the parametric regression problem into a quadratic programming problem. To demonstrate the efficiency of the proposed algorithm, numerical experiments are conducted. The proposed method is found to be feasible for the inverse boundary value problem of Poisson equation.