bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Investigation of Archimedes Screw Turbines under Low-Head Conditions
Authors: Maulana Muhammad Ilham , Ahmad Syuhada  , Deendarlianto Deendarlianto , Syam Syafiie , Aulia Fikri Fiqi
Published: October 2024

The development of screw turbines for micro-hydro power generation has garnered heightened interest lately, attributed to their capability to perform efficiently despite low head and low discharge. The present numerical work aims to evaluate the prospect of low-head water energy widely available in the Aceh region. In this region, the Archimedes Screw turbine is the most commonly used. In the present numerical study, the characteristics of the Archimedes screw turbine were studied under the constant of the head of 1 meter and the inclination angle of 30o, with the flow rate served as the varying parameter. In the simulation, a three-dimensional numerical investigation of pressure characteristics, flow velocity, and kinetic energy turbulence due to the change in the flow rates was carried out using the Navier-Stokes equations. Next, the turbulence model of K-Epsilon was also implemented. The comparisons between the experimental and the simulation results were carried out to ensure the accuracy of the simulation model, and the results indicated that the changes in flow rates have a marked influence on pressure distribution, the flow velocity field, and turbulent kinetic energy. It was found that the performance of the Archimedes double screw turbine was improved by increasing the flow rate due to the uniform distribution of pressure, flow velocity, and turbulent kinetic energy. Moreover, the optimum condition was achieved in a turbine with 8 screws. Therefore, maintaining the inflow rate is crucial as it significantly impacts the efficiency of the Archimedes Screw Turbine.
Numerical Analysis of the Influence of the Rolling Speed on the Cold Rolling under Specific Thermal Condition of the AA 5052-O Aluminum Alloy
Authors: Nawi Sami Ali , Mohammed Hussein Burhan , Jasim Ayad Naseef , Sharaf Hussein Kadhim , Muhammad Muzher Taha
Published: October 2024

In this study, the behavior of the rolling process of the AA 5052 aluminum alloy plate has been investigated using numerical data. An FEM technique was utilized in order to make a prediction regarding the impact that the rolling speed has on the cold rolling of the AA 5052-O aluminum alloy. In order to carry out the simulation procedure, the static structure tool was considered. The geometry of the situation. The total deformation, stresses, including von and normal stresses, and energy have all been the subject of investigation for the simulation that is now being performed. In both the axial and radial directions, the deformation has been investigated using numerical methods. It is possible to get a maximum result of 550 and 140 mm, respectively. at a speed of 200 revolutions per minute, the energy reached 8 kilojoules. It has been established that both normal and von mises stresses have been established. A total of 3.6 and 1.9 MPa are the numerical results that the stress has produced.
Andragogia e educação popular: concepções, políticas e práticas
Authors: Cascardo Benedito Fernando Honório , Santos Douglas Rodrigo Cursino dos , Viana André Luis Pullig
Published: October 2024

Introdução: A educação de adultos, conhecida como andragogia, e a educação popular compartilham um objetivo comum: promover a autonomia e a participação ativa dos educandos no processo de aprendizagem. Objetivo: Baseando-se em teorias de Paulo Freire e Malcolm Knowles, este artigo explora como as concepções teóricas de ambos os campos influenciam políticas educacionais e práticas pedagógicas. Método: Através de uma revisão de literatura e análise de estudos de caso, são destacadas as interseções entre andragogia e educação popular, enfatizando a importância de uma abordagem centrada no educando, que valorize suas experiências e conhecimentos prévios. Resultados: Conclui-se que a integração dessas abordagens pode fortalecer práticas educacionais que promovam a emancipação e a transformação social.
Effects of Trichoderma Fermented Biourine Dosage on the Growth of Two Shallot Varieties
Authors: Astiko Wahyu , Sudantha I Made
Published: October 2024

This study aims to determine the effect of Trichoderma harzianum fermented biourine dosage on the growth of two shallot (Allium ascolonicum L.) varieties. The research employed an experimental method with a Factorial Completely Randomized Design (CRD) consisting of two factors: biourine dosage and shallot variety. The biourine dosage levels were: q0 = Without biourine application, q1 = 5 ml/plant, q2 = 15 ml/plant, q3 = 25 ml/plant, and q4 = 35 ml/plant. The shallot varieties tested were v1 = Keta Monca and v2 = Bali Karet. In total, 10 treatment combinations of biourine dosage and variety were evaluated. The results showed that the most effective biourine dosage for promoting shallot growth was 35 ml (q4). This dosage significantly increased plant height, number of leaves, number of tillers, fresh stover, dry stover, fresh tuber weight, and dry tuber weight. The Keta Monca variety outperformed in terms of number of tillers, fresh tuber weight, and dry tuber weight, while the Bali Karet variety exhibited greater plant height, number of leaves, fresh stover, and dry stover. Significant interactions between biourine dosage and variety were observed in parameters such as plant height at 3 and 4 weeks after planting (WAP), number of leaves at 1, 4, and 5 WAP, number of tillers at 6 and 7 WAP, fresh tuber weight, and dry tuber weight.
A Meta-analysis on the Influence of Authoritarian Parenting Style on Adolescents' Social Anxiety
Authors: P. T Hiba.
Published: October 2024

Aim To understand the influence of authoritarian parenting style in adolescents' social anxiety.  Methodology Previous research papers and articles published on this topic were reviewed and comprehended through google scholar and pub med etc that were previously used by other scholars. After collecting various studies, these studies were reviewed and reached a conclusion.  Literature Review This study comprises various papers conducted by researchers on the impact of authoritarian parenting on adolescents’ social anxiety. These studies were assumed to be the data for this present study. This study was successfully completed by discussing the findings of these already existing studies.  Discussion and Interpretation Many studies have found that authoritarian parenting has a significant direct effect on social anxiety in adolescents. The cold and rejecting parenting enhances fear in the child. As the child grows into adolescence, the teen may withdraw from social situations and isolate himself or herself solely because of the fear of being judged and scrutinized by others.  Conclusion It is suggested that parents should not adopt authoritarian parenting to upbring the child. Girls were reported to be higher in social anxiety as compared to boys.
Efficient MAC Unit Design for DSP Processors Using Multiplication and Accumulation Operations
Authors: V Gayathri , M Kathirvelu , P Yogeswari
Published: October 2024

Digital signal processors are essential for intricate processes like filtering and convolution. CPU core integration into a single Integrated Circuit (IC) is widespread to satisfy growing processing needs. Multiply and Accumulate (MAC) units are essential for repeated addition and multiplication in DSP. Performance of the MAC unit has a big impact on the total speed of the DSP algorithm. It is suggested to create a high-speed MAC unit with a pipelined Brent Kung (BK) Adder design and the Vedic multiplier technique. A comparative study with a standard Brent Kung adder and a 32-bit MAC unit reveals that the suggested MAC unit has a speed boost of almost five times. The significance of novel designs, such as the pipelined brent kung Adder architecture and the Vedic multiplier technique, in improving MAC unit performance for digital signal processing applications is highlighted by the synthesis findings. All the designs were implemented on cadence genus EDA tool using Verilog code.
Analysis of the Validity of Inter-Religious Marriages Held Abroad
Authors: PERMANA Gede Esa Surya , SUJANA I Nyoman , AGUNG Anak Agung Istri
Published: October 2024

Purpose: Marriage according to the Marriage Law is valid if it is carried out according to the laws of each religion and its beliefs. Therefore, interfaith marriages are prohibited in Indonesia. Many couples of different religions who want to get married choose to get married abroad so that the marriage is considered valid by the state and has legal certainty.Methodology:The research method used is normative legal research, which uses primary and secondary legal sources and is then analyzed qualitatively using the deductive method.Findings: Normative legal certainty is generally seen from the validity of regulations made and enacted with certainty because they regulate clearly and logically. Marriages that take place abroad must be reported to the population and civil registration office according to the place of residence of the couple who are getting married, especially as the results of my interview as a researcher, the couple who got married abroad reported their marriage to the population and civil registration office in Bali, especially to the population and civil registration office of Badung Regency.Implication:A marriage conducted abroad is valid if it is conducted according to the laws in force in the country where the marriage is conducted and does not violate the provisions of the legal system in Indonesia. The marriage is considered valid in the legal system in Indonesia if it has been reported and recorded at the Population and Civil Registration Service, where the husband and wife who conducted the marriage abroad reside.
Como entender o conflito Israel –Palestina desde a perspectiva do Direito Internacional Humanitário
Authors: Llanos Villanueva Luz Amparo
Published: October 2024

O presente artigo apresenta uma linha de análise que discorre ente o Direito Internacional e a Política Internacional com elementos chaves como a importância da história de ambos os povos envolvidos nesse conflito. A pergunta principal que a autora tenta colocar para o leitor é: até que ponto neste polêmico conflito histórico as organizações internacionais vêm cumprindo seus papéis levando em conta o marco jurídico que as legitimam. A primeira parte introduz ao leitor um breve resumo daqueles fatos históricos mais importantes que colocam esse conflito como um dos mais importantes na atualidade. Na segunda parte, o artigo apresenta a importância do direito humanitário e do seu cumprimento diante do conflito Israel – Palestina. E por último a autora ressalta um elemento não pouco comum para analisar o conflito, e é a participação das Nações Unidas no auxílio no Conflito Israel –Palestina, mas principalmente a possibilidade de robustecer as forças de paz das Nações Unidas para a ajuda humanitária que vá da mão dos objetivos básicos do direito internacional humanitário.
Informal irrigated vegetable value chains in urban Ghana: potential to improve food safety through changing stakeholder practices
Authors: Galibourg David , Amankwaa Ebenezer F. , Gough Katherine V. , Scott Rebecca
Published: October 2024

Contaminated vegetables grown and consumed in cities of the global South have adverse public health consequences. Through interviews with farmers, traders, consumers and institutional representatives, this article explores why stakeholders in the irrigated vegetable value chain in Accra continue unsafe practices. The multi-stakeholder data are analysed by combining a behavioural model with a framework of complex stakeholder interactions. Arguably, a systemic approach would help meet stakeholders’ opportunity, capability and motivation needs and actualise current efforts to promote safe practices. Findings indicate the need for all stakeholders to develop a shared understanding of each other’s practices and co-design flexible arrangements that better integrate their diverse rationales, knowledge and constraints. Improving hygiene and food safety from farm to fork requires political commitment that accounts for land tenure insecurity and the high cost of safe water.

This article was published open access under a CC BY licence:
https://creativecommons.org/licences/by/4.0
.
Variabilities of Methanol Maser and Thermal Molecular Lines from an Accretion Burst Source G358.93-0.03
Authors: Zhang Shi-jie , Chen Xi , Zhang Yan-Kun , Miao Dan , Lu Deng-Rong , Ju Bing-Gang
Published: October 2024

From 2019 January to June, the high-mass young stellar object G358.93-0.03 underwent a remarkable accretion burst. Detecting variations in the physical and kinematic environments during episodic accretion is essential for exploring such events. Searching for new maser or molecular lines and monitoring their variability during the accretion burst and postburst stages is feasible for such a study. Using the Purple Mountain Observatory 13.7 m telescope, we carried out monitoring of methanol masers and molecular lines toward G358.93-0.03 in the 3 mm band during the burst (2019 March to June) and postburst stages (2022 October). In addition to the previously abundant detection of the methanol maser lines in the burst stage, eight new methanol maser lines were detected, identified from transitions at 85.57, 93.20, 94.54, 94.82, 99.77, 102.96, 104.35, and 104.41 GHz. Their integrated intensity exhibited an exponential decline during the burst stage, likely associated with the decay process of the accretion burst. None of the eight methanol maser lines were detected in the postburst stage. Besides maser lines, 12 thermal molecular lines were detected in both the burst and postburst stages. Variability of some of them was observed in both stages, but most notably, the ratio of HCO+/N2H+ increased significantly in the burst stage compared to the postburst stage. It is likely caused by the changes of both molecular lines during the burst and postburst stages due to the heating process induced by episodic accretion. Therefore, the comparison of their line intensity ratios might offer a new method for tracing episodic accretion bursts.
Discovery of 118 New Ultracool Dwarf Candidates Using Machine-learning Techniques
Authors: Brooks Hunter , Caselden Dan , Kirkpatrick J. Davy , Raghu Yadukrishna , Elachi Charles A. , Grigorian Jake , Trek Asa , Washburn Andrew , Higashimura 東 Hiro 村滉 , Meisner Aaron M. , Schneider Adam C. , Faherty Jacqueline K. , Marocco Federico , Gelino Christopher R. , Gagné Jonathan , Bickle Thomas P. , Tang Shih-Yun , Rothermich Austin , Burgasser Adam J. , Kuchner Marc J. , Beaulieu Paul , Bell John , Colin Guillaume , Colombo Giovanni , Dereveanco Alexandru , Flores Deiby Pozo , Glebov Konstantin , Gramaize Leopold , Hamlet Les , Hinckley Ken , Kabatnik Martin , Kiwy Frank , Martin David W. , Palma Méndez Raúl F. , Pendrill Billy , Ruiz Lizzeth , Sanchez John , Sainio Arttu , Schümann Jörg , Schonau Manfred , Tanner Christopher , Stevnbak Nikolaj , Stenner Andres , Thévenot Melina , Thakur Vinod , Voloshin Nikita V. , Wȩdracki Zbigniew ,   The Backyard Worlds: Planet 9 Collaboration
Published: October 2024

We present the discovery of 118 new ultracool dwarf candidates, discovered using a new machine-learning tool, named SMDET, applied to time-series images from the Wide-field Infrared Survey Explorer. We gathered photometric and astrometric data to estimate each candidate’s spectral type, distance, and tangential velocity. This sample has a photometrically estimated spectral class distribution of 28 M dwarfs, 64 L dwarfs, and 18 T dwarfs. We also identify a T-subdwarf candidate, two extreme T-subdwarf candidates, and two candidate young ultracool dwarfs. Five objects did not have enough photometric data for any estimations to be made. To validate our estimated spectral types, spectra were collected for two objects, yielding confirmed spectral types of T5 (estimated T5) and T3 (estimated T4). Demonstrating the effectiveness of machine-learning tools as a new large-scale discovery technique.
Morphologies of Bright Complex Fast Radio Bursts with CHIME/FRB Voltage Data
Authors: Faber Jakob T. , Michilli Daniele , Mckinven Ryan , Su Jianing , Pearlman Aaron B. , Nimmo Kenzie , Main Robert A. , Kaspi Victoria , Bhardwaj Mohit , Chatterjee Shami , Curtin Alice P. , Dobbs Matt , Eadie Gwendolyn , Gaensler B. M. , Kader Zarif , Leung Calvin , Masui Kiyoshi W. , Pandhi Ayush , Petroff Emily , Pleunis Ziggy , Rafiei-Ravandi Masoud , Sand Ketan R. , Scholz Paul , Shin Kaitlyn , Smith Kendrick , Stairs Ingrid
Published: October 2024

We present the discovery of 12 apparently nonrepeating fast radio burst (FRB) sources, detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. These sources, only one of which has been presented previously in the first CHIME/FRB catalog, were selected from a database comprising

O
(

10

3

)

CHIME/FRB full-array raw voltage data recordings, based on their large signal-to-noise ratios and complex morphologies. Our study examines the time-frequency characteristics of these bursts, including drifting, microstructure, and periodicities. The events in this sample display a variety of unique drifting phenomenologies that deviate from the linear negative drifting phenomenon seen in many repeating FRBs, and motivate a possible new framework for classifying drifting archetypes. Additionally, we detect microstructure features of duration ≲50 μs in seven events, with some as narrow as ≃7 μs. We find no evidence of significant periodicities between subburst components. Furthermore, we report the polarization characteristics of seven events, including their polarization fractions and Faraday rotation measures (RMs). The observed ∣RM∣ values span a wide range of 17.24(2)–328.06(2) rad m−2, with apparent linear polarization fractions between 0.340(1) and 0.946(3). The morphological properties of the bursts in our sample appear broadly consistent with predictions from both relativistic shock and magnetospheric models of FRB emission, as well as propagation through discrete ionized plasma structures. We address these models and discuss how they can be tested using our improved understanding of morphological archetypes.
Jets from the Upper Scorpius Variable Young Star System 2MASS J16075796-2040087 via KECK/HIRES Spectro-astrometry
Authors: Whelan Emma T. , Keppler Miriam , Turner Neal J. , Pascucci Ilaria , Hamden Erika , Hoadley Keri , Fang Min
Published: October 2024

2MASS J16075796-2040087 is an ∼5 Myr young star in Upper Sco with evidence for accretion bursts on a timescale of about 15 days and, uncommonly for its age, outflows traced by multicomponent forbidden emission lines (FELs). The accretion bursts may be triggered by a companion at ∼4.6 au. We analyze HIRES spectra optimised for spectro-astrometry to better understand the origin of the several FEL velocity components and determine whether a magnetohydrodynamic (MHD) disk wind is present. The FEL high-velocity component (HVC) traces an asymmetric, bipolar jet ∼700 au long. The jet’s position angle ∼ 277° is not perpendicular to the disk. The lower-velocity emission, classified previously as a disk wind low-velocity component, is found to have more in common with the HVC and overall it is not possible to identify an MHD disk wind component. The spectro-astrometric signal of the low-velocity emission resembles those of jets and its density and ionisation fraction fall into the range of HVCs. We suggest a scenario where the accretion bursts due to the close companion power the jets past the age where such activity ends around most stars. The low-velocity emission here could come from a slow jet launched near the close companion and this emission would be blended with emission from the MHD wind.
Variable Stars in M31 Stellar Clusters from the Panchromatic Hubble Andromeda Treasury
Authors: Smith Richard , Patel Avi , Soraisam Monika D. , Guhathakurta Puragra , Tadepalli Pranav , Zhu Sally , Liu Joseph , Girardi Léo , Johnson L. Clifton , Mukherjee Sagnick , Olsen Knut A. G. , Williams Benjamin F.
Published: October 2024

Variable stars in stellar clusters can offer key constraints on stellar evolution and pulsation models, utilizing estimates of host cluster properties to constrain stellar physical parameters. We present a catalog of 86 luminous (F814W < 19) variable stars in M31 clusters identified by mining the archival Panchromatic Hubble Andromeda Treasury (PHAT) survey using a combination of statistical analysis of sparse PHAT light curves and difference imaging. We determine the evolutionary phases and initial masses of these variable stars by matching them with theoretical isochrones generated using host cluster properties from the literature. We calculate the probability of PHAT photometry being blended due to the highly crowded nature of cluster environments for each cluster-variable star, using these probabilities to inform our level of confidence in the derived properties of each star. Our 86 cluster-variable stars have initial masses between 0.8 and 67 M
⊙. Their evolutionary phases span the main sequence, more evolved hydrogen- and helium-burning phases, and the post–asymptotic giant branch. We identify numerous candidate variable star types: RV Tauri variables, red supergiants, and slowly pulsating B-type supergiants, along with Wolf–Rayet stars, α Cygni and Mira variables, a classical Cepheid, and a possible superasymptotic giant. We characterize 12 cluster-variable stars at higher confidence based on their difference image quality and lower blending probability. Ours is the first systematic study of variable stars in extragalactic stellar clusters leveraging the superior resolution of the Hubble Space Telescope and demonstrating the unique power of stellar clusters in constraining the fundamental properties of variable stars.
Sunyaev–Zeldovich Signals from L* Galaxies: Observations, Analytics, and Simulations
Authors: Oren Yossi , Sternberg Amiel , McKee Christopher F. , Faerman Yakov , Genel Shy
Published: October 2024

We analyze measurements of the thermal Sunyaev–Zeldovich (tSZ) effect arising in the circumgalactic medium (CGM) of L* galaxies, reported by J. N. Bregman et al. (B+22) and S. Das et al. (D+23). In our analysis, we use the Y. Faerman et al. CGM models, a new power-law model (PLM), and the TNG100 simulation. For a given M
vir, our PLM has four parameters: the fraction, f
hCGM, of the halo baryon mass in hot CGM gas, the ratio, ϕ

T
, of the actual gas temperature at the virial radius to the virial temperature, and the power-law indices, a

P,th and a

n
for the thermal electron pressure and the hydrogen nucleon density. The B+22 Compton-y profile implies steep electron pressure slopes (a

P,th ≃ 2). For isothermal conditions, the temperature is at least 1.1 × 106 K, with a hot CGM gas mass of up to 3.5 × 1011
M
⊙ for a virial mass of 2.75 × 1012
M
⊙. However, if isothermal, the gas must be expanding out of the halos. An isentropic equation of state is favored for which hydrostatic equilibrium is possible. The B+22 and D+23 results are consistent with each other and with recent (0.5–2 keV) CGM X-ray observations of Milky Way mass systems. For M
vir ≃ 3 × 1012
M
⊙, the scaled Compton pressure integrals,

E

(
z
)

−
2

/

3

Y

500

/

M

vir
,
12

5

/

3

, lie in the narrow range, 2.5 × 10−4–5.0 × 10−4 kpc2, for all three sets of observations. TNG100 underpredicts the tSZ parameters by factors ∼0.5 dex for the L* galaxies, suggesting that the feedback strengths and CGM gas losses are overestimated in the simulated halos at these mass scales.
Tayler Instability Revisited
Authors: Skoutnev Valentin A. , Beloborodov Andrei M.
Published: October 2024

Tayler instability of toroidal magnetic fields B

ϕ
is broadly invoked as a trigger for turbulence and angular momentum transport in stars. This paper presents a systematic revision of the linear stability analysis for a rotating, magnetized, and stably stratified star. For plausible configurations of B

ϕ
, instability requires diffusive processes: viscosity, magnetic diffusivity, or thermal/compositional diffusion. Our results reveal a new physical picture, demonstrating how different diffusive effects independently trigger instability of two types of waves in the rotating star: magnetostrophic waves and inertial waves. It develops via overstability of the waves, whose growth rate sharply peaks at some characteristic wavenumbers. We determine instability conditions for each wave branch and find the characteristic wavenumbers. The results are qualitatively different for stars with magnetic Prandtl number Pm ≪ 1 (e.g., the Sun) and Pm ≫ 1 (e.g., protoneutron stars). The parameter dependence of unstable modes suggests a nonuniversal scaling of the possible Tayler–Spruit dynamo.
Contactless Manipulation and Raman Analysis of Cometary Analogs and Micrometeorites by Acoustic Levitation
Authors: Ferretti S. , Marrara S. , Bronte Ciriza D. , Magazzù A. , Foti A. , Gucciardi P. G. , Musolino A. , Folco L. , Della Corte V. , Rotundi A. , Saija R. , Mandanici A. , Maragò O. M. , Donato M. G.
Published: October 2024

Extraterrestrial material collected during space missions is highly exposed to contamination issues during on-Earth analysis. Although high-protection-level protocols were developed, to minimize the contamination due to sample manipulation and the substrate contribution an optimal strategy is to perform in situ analysis with contactless techniques. Optical and acoustic trapping represent ideal candidates for contactless manipulation and analysis of nanometer-to-millimeter-sized particles. Here, we show results of the manipulation of cometary analogs and micrometeorite samples using a single-axis acoustic levitator. The investigation of the particle dynamics in the trap allows the calculation of the trap spring constants that are found in the mN/m range. In addition, we collect the Raman spectra of two levitated fragments of Saratov meteorite, demonstrating that acoustic levitation can be effectively used for the contactless and low-contamination characterization of samples of interest in astrophysics.
LMC-driven Anisotropic Boosts in Stream–Subhalo Interactions
Authors: Arora Arpit , Garavito-Camargo Nicolás , Sanderson Robyn E. , Cunningham Emily C. , Wetzel Andrew , Panithanpaisal Nondh , Barry Megan
Published: October 2024

Dark matter subhalos are predicted to perturb stellar streams; stream morphologies and dynamics can, therefore, constrain the mass distribution of subhalos. Using FIRE-2 simulations of Milky Way–mass galaxies, we demonstrate that the presence of an LMC analog significantly changes stream–subhalo encounter rates. The LMC analog brings in many subhalos, increasing encounter rates for streams near the massive satellite by 10%–40%. Additionally, the LMC analog displaces the host from its center of mass (inducing reflex motion), which causes a north–south asymmetry in the density and radial velocity distributions of subhalos. This asymmetry, combined with the presence of LMC-analog subhalos, causes encounter rates at the same distance to vary by 50%–70% across the sky, particularly in regions opposite the LMC analog. Furthermore, the LMC analog induces a density wake in the host's dark matter halo, further boosting the encounter rates near the LMC analog. We also explore how stream orbital properties affect encounter rates, finding up to a 50% increase for streams moving retrograde to the LMC analog’s orbit in the opposite quadrant. Finally, we report the encounter rates for Milky Way streams within the context of our simulations, both with and without the presence of an LMC analog. The dependence of encounter rates on stream location, orbit, and their position relative to the LMC has important implications for where to search for streams with spurs and gaps in the Milky Way.
Instability and Evolution of Shocked Clouds Formed by Orthogonal Collisions between Magnetized Filamentary Molecular Clouds
Authors: Kashiwagi Raiga , Iwasaki Kazunari , Tomisaka Kohji
Published: October 2024

Filamentary molecular clouds are recognized as primary sites for the formation of stars. Specifically, regions characterized by the overlapping point of multiple filaments, known as hub regions, are often associated with active star formation. However, the formation mechanism of this hub structure is not well understood. Therefore, to understand the formation mechanism and star formation in hub structures, as a first step, we investigate the orthogonal collisions between two filaments using three-dimensional ideal magnetohydrodynamical simulations. As a model of initial filaments, we use an infinitely long filament in magnetohydrostatic equilibrium under a global magnetic field running perpendicular to the filament axis. Two identical equilibrium filaments, sharing the same magnetic flux, are arranged with their long axes perpendicular to each other and given an initial velocity perpendicular to their long axes to replicate an orthogonal collision. We find three types of evolution after the shocked cloud is formed: collapse, stable, and expansion modes. The energy balance just after the filaments completely collide explains the future evolution of the shocked cloud. If the magnitude of gravitational energy is larger than the sum of the kinetic, thermal, and magnetic energies, the shocked cloud evolves in collapse mode. If the magnitude of gravitational energy is less than the sum of these energies, the cloud evolves in stable mode when the kinetic energy is relatively small and in expansion mode when the kinetic energy is sufficiently large.
Kinematics of Supernova Remnants Using Multiepoch Maximum Likelihood Estimation: Chandra Observation of Cassiopeia A as an Example
Authors: Sakai Yusuke , Yamada Shinya , Sato Toshiki , Hayakawa Ryota , Kominato Nao
Published: October 2024

Decadal changes in a nearby supernova remnant (SNR) were analyzed using a multiepoch maximum likelihood estimation (MLE) approach. To achieve greater accuracy in capturing the dynamics of SNRs, kinematic features and point-spread function effects were integrated into the MLE framework. Using Cassiopeia A as a representative example, data obtained by the Chandra X-ray Observatory in 2000, 2009, and 2019 were utilized. The proposed multiepoch MLE was qualitatively and quantitatively demonstrated to provide accurate estimates of various motions, including shock waves and faint features, across all regions. To investigate asymmetric structures, such as singular components that deviate from the direction of expansion, the MLE method was extended to combine multiple computational domains and classify kinematic properties using the k-means algorithm. This approach allowed for the mapping of different physical states onto the image, and one classified component was suggested to interact with circumstellar material by comparison with infrared observations from the James Webb Space Telescope. Thus, this technique will help quantify the dynamics of SNRs and discover their unique evolution.
Global Analysis of the Extended Decreases in Cosmic Rays Observed with Worldwide Networks of Neutron Monitors and Muon Detectors: Temporal Variation of the Rigidity Spectrum and Its Implication
Authors: Munakata K. , Hayashi Y. , Kozai M. , Kato C. , Miyashita N. , Kataoka R. , Kadokura A. , Miyake S. , Iwai K. , Echer E. , Dal Lago A. , Rockenbach M. , Schuch N. J. , Bageston J. V. , Braga C. R. , Al Jassar H. K. , Sharma M. M. , Duldig M. L. , Humble J. E. , Sabbah I. , Evenson P. , Kuwabara T. , Kóta J.
Published: October 2024

This paper presents the global analysis of two extended decreases in the galactic cosmic-ray intensity observed by worldwide networks of ground-based detectors in 2012. This analysis is capable of separately deriving the cosmic-ray density (or omnidirectional intensity) and anisotropy, each as a function of time and rigidity. A simple diffusion model along the spiral field line between Earth and a cosmic-ray barrier indicates the long duration of these events, resulting from about 190° eastern extent of a barrier such as an interplanetary shock followed by the sheath region and/or the corotating interaction region (CIR). It is suggested that the coronal mass ejection merging with and compressing the preexisting CIR at its flank can produce such an extended barrier. The derived rigidity spectra of the density and anisotropy both vary in time during each event period. In particular we find that the temporal feature of the “phantom Forbush decrease (FD)” reported in an analyzed period is dependent on rigidity, and looks quite different at different rigidities. From these rigidity spectra of the density and anisotropy, we derive the rigidity spectrum of the average parallel mean free path of pitch angle scattering along the spiral field line and infer the power spectrum of the magnetic fluctuation and its temporal variation. The possible physical cause of the strong rigidity dependence of the phantom FD is also discussed. These results demonstrate the high-energy cosmic rays observed at Earth responding to remote space weather.
AstroSat and Insight-HXMT Observations of the Long-period X-Ray Pulsar 4U 2206+54
Authors: Epili Prahlad R. , Wang Wei
Published: October 2024

We report the timing and spectral studies of the accreting X-ray pulsar 4U 2206+54 using AstroSat and Insight-HXMT observations taken in 2016 and 2020 respectively. X-ray pulsations from the system are detected by both missions. The AstroSat discovered a significant periodic signal at ∼5619 s in 2016, and Insight-HXMT found a pulsation period at ∼5291 s in 2020. A comparison of its spin-period evolution with the present spin-period estimates shows that the neutron star in 4U 2206+54 now has recently been undergoing a spin-up episode after attaining to its slow pulsations of 5750 s around 2015 from its prolonged spin-down phase. The present average spin-up rate of the pulsar is found to be at ∼1.2 × 10−13 Hz s−1. The phase-averaged spectra of the pulsar in 1–60 keV could be explained with a high-energy cutoff power-law continuum model; no evident line features are found with AstroSat. The application of Comptonization models such as comptt and compmag to the phase-averaged spectra of 4U 2206+54 reveals a hotter source photon region near the pulsar with an emission size extending to ∼2–2.8 km. Using the quasi-spherical settling accretion theory, we explain the present spin-up and the possibility of the strong magnetic field of the pulsar.
Broadening the Canonical Picture of EUV-driven Photoevaporation of Accretion Disks
Authors: Nakatani Riouhei , Turner Neal J. , Takasao Shinsuke
Published: October 2024

Photoevaporation driven by hydrogen-ionizing extreme-ultraviolet (EUV) radiation profoundly shapes the lives of diverse astrophysical objects. We construct an analytical model accounting for the finite timescales of photoheating and photoionization and apply it to the dispersal of protoplanetary disks. The model yields improved estimates for the ionization, temperature, and velocity versus distance from the central source when compared to the classical picture of fully ionized and isothermal winds with temperatures ≈104 K and speeds ≈10 km s−1. In contrast to the classical picture, the photoevaporative winds take on several distinct hydrodynamical and thermochemical states depending on the central star’s EUV emission rate and spectral hardness: T Tauri stars with EUV luminosities around 1030 erg s−1 drive nonisothermal ionized disk winds at lower temperatures than the classical value if the spectrum is soft, with an average deposited energy per photoionization less than about 3.7 eV. If, however, the spectrum is hard, the winds tend to be atomic and isothermal at most disk radii. For lower EUV intensities, even with soft spectra, atomic winds can emerge beyond ∼10 au through advection. We show that these predictions are in general agreement with detailed radiation hydrodynamics calculations. The model furthermore illustrates how the energy efficiency of photoevaporation varies with the intensity and spectral hardness of the EUV illumination, as well as addressing discrepancies in the literature around the effectiveness of X-ray photoevaporation. The findings highlight the importance of the photoheating and photoionization timescales both for modeling and for understanding winds’ observed behavior.
ALMA Detection of Masers and Dasars in the Hydrogen Recombination Lines of the Planetary Nebula Mz3
Authors: Abraham Zulema , Beaklini Pedro P. B. , Aleman Isabel , Sahai Raghvendra , Zijlstra Albert , Akras Stavros , Gonçalves Denise R. , Ueta Toshiya
Published: October 2024

The hydrogen recombination lines H30α, H40α, H42α, H50β, and H57γ and the underlying bremsstrahlung continuum emission were detected with ALMA in the bipolar nebula Mz3. The source was not spatially resolved, but the velocity profile of the H30α line shows clear indication of maser amplification, confirming previous reports of laser amplification in the far-infrared H recombination lines observed with Herschel Space Observatory. Comparison between the flux densities of the H50β, H40α, and H42α lines show overcooling, or darkness amplification by stimulated absorption (dasar effect) at the LSR velocity of about −25 km s−1, which constrains the density of the absorbing region to about 103 cm−3. The H30α line, on the other hand, presents maser lines at LSR velocities of −69 and −98 km s−1, which indicates ionized gas with densities close to 107 cm−3. Although the source of emission was not resolved, it was possible to find the central position of the images for each velocity interval, which resulted in a well defined position–velocity distribution.
On the 1/f Spectrum in Slow Solar Wind Turbulence: The Role of Alfvénicity
Authors: Dorseth Mason , Bourouaine Sofiane , Perez Jean C.
Published: October 2024

The slow solar wind has been recently observed to have a number of intervals that are dominated by large-scale Alfvénic fluctuations, especially within 1 au, with similar turbulence characteristics to those found in fast wind streams, including a 1/f range. These results suggest that the slow solar wind exists in at least two flavors: the typical slow wind that generally does not exhibit a 1/f range and an Alfvénic wind that is more similar to fast wind streams. The Alfvénic slow wind is usually differentiated from the typical slow wind (not dominated by Alfvénic fluctuations) by the normalized cross helicity, σ

c
. Values of ∣σ

c
∣ near unity are associated with Alfvénic fluctuations, whereas values near zero are typically thought of as non-Alfvénic. This classification by cross helicity excludes the case of solar wind fluctuations dominated by balanced Alfvénic turbulence, i.e., the turbulence regime where there is equal energy flux of counterpropagating fluctuations propagating along the mean field. We use a large statistical analysis to isolate intervals of slow wind at 1 au in a 20 yr period of Wind data. These intervals are sorted into subsets corresponding to the type of slow wind via the mean values of their magnetic compressibility and cross helicity. Our analysis finds several intervals of low-cross-helicity slow wind dominated by balanced Alfvénic turbulence, which possess similar characteristics found in high-cross-helicity streams. Our results support the conclusion that a 1/f spectrum may be a property associated with streams dominated by Alfvénic turbulence, whether the turbulence is balanced or imbalanced.
Systematic camera trapping survey for terrestrial vertebrates in Xuan Lien Nature Reserve, Vietnam
Authors: Nguyen Thanh , Luu Anh , Pham Hung , Nguyen Ha , Pham Tam , Nguyen Mai , Le Minh , Nguyen Anh
Published: October 2024

Xuan Lien Nature Reserve was established in 1999 to protect important habitats and wildlife in the northern part of the Annamites in Vietnam. While Xuan Lien is home to many threatened species, it has experienced a high level of human disturbance over the last decades. To document and provide baseline data on the status and distribution of the terrestrial vertebrate fauna community in the region, we conducted a systematic camera trapping survey in Xuan Lien Nature Reserve in 2023. The data collected during the survey will help design proper conservation measures to better conserve the remaining species.

Our study investigates and updates the species richness of mid- to large-sized terrestrial vertebrates, thus providing essential information for developing conservation strategies in Xuan Lien Nature Reserve, Vietnam. As camera traps were set up in a grid-based design, our survey also generated the first-ever systematic data for terrestrial vertebrate fauna in the area. The study covers approximately 21,000 hectares (about 77% of the area), using 35 camera trap stations; each station consists of two cameras. In total, the final dataset consists of 6,276 trap nights, recording at least 46 species in 39 genera. The results suggest that Xuan Lien is a key stronghold for small carnivores, based on the diversity of such species groups in the Reserve. We failed to detect the previously documented Roosevelt’s muntjac (Muntiacus rooseveltorum Osgood, 1932) and we only documented a single record of the northern red muntjac (Muntiacus vaginalis Boddaert, 1785). Our survey confirms the severity of overhunting and other anthropogenic threats to the mammal fauna, especially ungulates, in the Reserve.
Y a-t-il des fictions musicales ?
Authors: Pouradier Maud
Published: October 2024

Contrairement à Aristote, les hypothèses réalistes modernes ne considèrent pas qu’une musique puisse être littéralement colérique ou pathétique. Dès lors que ce n’est que métaphoriquement ou imaginairement que la musique peut être décrite ainsi, se pose la question du sujet de ces prédicats. L’hypothèse de Kendall Walton est qu’il y a bien une fiction musicale, même dans les œuvres strictement instrumentales. L’auditeur feint de croire que quelqu’un ou quelque chose est mélancolique ou en colère, ce qui suffit pour parler de fiction musicale, puisqu’un jeu de faire-semblant est impliqué. Mais contrairement à l’œuvre littéraire, l’œuvre musicale ne produit pas un monde fictionnel.
Entretien avec Jean-Michel Beaudet
Authors: Lantoine Jacques-Louis , Beaudet Jean-Michel
Published: October 2024

Jean-Michel Beaudet est professeur d’ethnomusicologie à l’Université Paris-Nanterre. Spécialiste de la musique et de la danse amérindienne, il a publié en 1997 Souffles d’Amazonie. Les orchestres tule des Wayãpi , accompagné d’un CD qui restitue les enregistrements pratiqués lors de son séjour auprès des Wayãpi, et en 2010 Nous danserons jusqu’à l’aube. Essai d’ethnologie mouvementée en Amazonie , Paris, CTHS. Plus récemment, il a fait paraître Jouer, danser, boire. Carnets d’ethnographies musicales aux Éditions de l’EHESS, 2017, qui mêle réflexions sur la pratique de l’ethnologie et souvenirs relatifs à son travail de terrain, qu’il conçoit moins comme une étude sur qu’une pratique avec les personnes rencontrées lors de ses différents voyages au Brésil (1975), en Guyane (1977-2023), en Nouvelle-Calédonie (1984-1988) – qui certes n’est pas en Amazonie – puis en Bolivie (1992-1998).
Crénobalnéothérapie en France et en Italie
Authors: Danan Jane-Laure , Massardier Mathilde , Fioravanti Antonella , Françon Alain , Kanny Gisèle
Published: October 2024

Introduction : La revue de la littérature compare l’efficacité des formats de cure en France et en Italie qui différent dans la durée (12 jours versus 18 jours), le nombre et le type de soins quotidiens chez les personnes souffrant de gonarthrose, pathologie rhumatologique fréquente. Méthode : La méthode Prisma 2020 et sa checklist de 27 items ont été utilisées pour réaliser la revue de littérature de l’efficacité clinique du traitement thermal de la gonarthrose en France et en Italie. Cinq bases de données ont été explorées en utilisant des mots clés traduits en anglais, français et italiens. Le risque de biais a été évalué par la grille Clear NTP. Résultats : Parmi 1007 publications, 7 études françaises et 8 études italiennes ont été sélectionnées. La durée du traitement thermal était conventionnelle pour 5 études françaises et 7 italiennes. L’offre de soins est plus large et plus diversifiée en France (au moins 4/j en France versus 1 à 2/j en Italie). La cure thermale est efficace dans les deux pays (France : 5 études/7, Italie : 6 études/8) en ce qui concerne l’échelle analogique de la douleur, le score Womac, l’indice algofonctionnel de Lequesne, la consommation d’antalgiques. Cet effet est montré rémanent de 3 et 6 mois. À noter que 6/8 études italiennes et 2/7 françaises ne reprenaient pas le schéma de traitement conventionnel national. Le thermalisme en France et en Italie diffère par la durée des cures thermales de 18 jours et 12 jours respectivement, une offre de soins quotidiens plus large et plus diversifiée pour la France (au moins 4 en France versus 1 à 2 en Italie). Les similitudes concernent la nature des soins, la participation financière d’un organisme de soins de santé, la nécessité d’une prescription médicale pour faire une cure et la surveillance médicale par le médecin thermal. Discussion et conclusion : Les études cliniques ont montré l’efficacité du traitement thermal de la gonarthrose en France et en Italie. Pour comparer l’efficacité du modèle thermal conventionnel français et italien, il apparaît nécessaire de réaliser une étude multicentrique franco-italienne respectant strictement les protocoles conventionnels des deux pays qui diffèrent dans la durée et le nombre de soins.
La crénobalnéothérapie gynécologique, expérience d’un médecin thermal
Authors: Dallançon Laure
Published: October 2024

L’Académie nationale de médecine, créée en 1820, reconnaît le thermalisme de même que l’OMS en 1986. En 1948 a été mise en place la prise en charge conventionnelle des cures thermales de trois semaines par l’Assurance maladie dans douze orientations dont la gynécologie. Cette dernière est tombée progressivement en désuétude au milieu du siècle dernier d’où une fréquentation très faible de nos jours, comme l’atteste mon expérience de 2012 à 2023 à Bourbon-l’Archambault, dont l’une des activités majeures est la rhumatologie. Se pose la question de l’avenir de la crénothérapie gynécologique.
À propos de l’activité sympatholytique de l’eau thermale de La Preste
Authors: Benoit Jean-Michel
Published: October 2024

L’existence d’un effet sympatholytique de l’eau de La Preste est anciennement connue. Elle est la conclusion d’un travail expérimental convaincant. Cette conclusion a été confirmée et précisée en revoyant certaines mesures débitmétriques réalisées dans la station et en ré-examinant des propriétés particulières de l’eau thermale. La conclusion de ce nouveau travail attribue à l’eau de La Preste des propriétés de blocage α1 similaires à celles des dérivés de la quinazoline, produits constituant le traitement médical actuel des dysuries masculines. Cette propriété de l’eau thermale fournit enfin l’explication d’une indication étonnante et fort ancienne de la cure à La Preste : les troubles urinaires de l’hypertrophie prostatique.