bluuebunny/crossref_metadata_2025_split huggingface dataset:
The environment around young eruptive stars
Authors: Zurlo A. , Weber P. , Pérez S. , Cieza L. , Ginski C. , van Holstein R. G. , Principe D. , Garufi A. , Hales A. , Kastner J. , Rigliaco E. , Ruane G. , Benisty M. , Manara C. 
Published: March 2024

Aims. Eruptive stars are a class of young stellar objects that show an abrupt increase in luminosity. These burst-like episodes are thought to dominate the stellar accretion process during the Class 0 to Class I stage. We present an overview of a survey of seven episodically accreting protostars carried out to study their potentially complex circumstellar surroundings.
Methods. The observations were performed with the instrument SPHERE, mounted at the Very Large Telescope. SPHERE is equipped with an extreme adaptive optics system that allows high-contrast imaging. We observed the eruptive stars in the H band with the near-infrared imager IRDIS and used the polarimeter to extract the polarized light scattered from the stars’ surroundings.
Results. We produced polarized light images for three FUor objects, Z CMa, V960 Mon, and FU Ori, and four EXor objects, XZ Tau, UZ Tau, NY Ori, and EX Lup. We calculated the intrinsic polarization fraction for all the observed stars. In all systems we registered scattered light from around the primary star. FU Ori and V960 Mon are surrounded by complex structures, including spiral-like features. In Z CMa, we detected a point source 0″​​.7 to the northeast of the primary. Based on the astrometric measurements from archival Keck/NIRC2 data, we find this source to be a third member of the system. Furthermore, Z CMa displays an outflow that extends for thousands of au. Unlike the other EXor objects in our sample, XZ Tau shows bright, extended scattered light structures that are also associated with an outflow on a scale of hundreds of au. The other EXors show relatively faint disk-like structures in the immediate vicinity of the coronagraph.
Conclusions. Each object shows a unique environment, but we classified the seven objects into three categories: systems with illuminated outflows, asymmetric arms, and faint disks. Asymmetric arms were only found around FUor objects, while faint disks seem to predominantly occur around EXors. Importantly, for Z CMa the detection of the faint extended structure calls into question previous interpretations of the system’s dynamic state. The streamer that was associated with a fly-by object turned out to be part of a huge outflow extending 6000 au.
Assessing Structural Transformation and the Potential Impacts of Belt and Road Initiative Projects in Africa
Authors: Li Weiping , Lu Saite 
Published: March 2024

AbstractInfrastructure development, central to the Belt and Road Initiative (BRI), is crucial for facilitating structural transformation. However, numerous critics contend that the Initiative serves as a tool for China to engage in debt-trap diplomacy, which fails to deliver actual development in Africa. Therefore, assessing whether BRI projects will facilitate the necessary structural transformation in these countries requires meticulous analysis. Given the extended project cycle typical of infrastructure development, evaluating the overall socioeconomic impacts of the BRI is challenging. Nonetheless, these projects are likely to be implemented as part of the expansion of China's existing model for overseas infrastructure projects. This model is characterized by a reliance on concessional loans and credit facilities for financing, and state-owned enterprises as contractors. Contrary to the debt-trap diplomacy narrative, our findings, based on panel data and staggered difference-in-differences analysis, indicate that Chinese projects have positively impacted multiple aspects of Africa's structural transformation process.
Second inflection point of supercooled water surface tension induced by hydrogen bonds: A molecular-dynamics study
Authors: Hrahsheh Fawaz , Jum’h Inshad , Wilemski Gerald 
Published: March 2024

Surface tension of supercooled water is a fundamental property in various scientific processes. In this study, we perform molecular dynamics simulations with the TIP4P-2005 model to investigate the surface tension of supercooled water down to 220 K. Our results show a second inflection point (SIP) in the surface tension at temperature TSIP ≈ 267.5 ± 2.3 K. Using an extended IAPWS-E functional fit for the water surface tension, we calculate the surface excess internal-energy and entropy terms of the excess Helmholtz free energy. Similar to prior studies [Wang et al., Phys. Chem. Chem. Phys. 21, 3360 (2019); Gorfer et al., J. Chem. Phys. 158, 054503 (2023)], our results show that the surface tension is governed by two driving forces: a surface excess entropy change above the SIP and a surface excess internal-energy change below it. We study hydrogen-bonding near the SIP because it is the main cause of water’s anomalous properties. With decreasing temperature, our results show that the entropy contribution to the surface tension reaches a maximum slightly below the SIP and then decreases. This is because the number of hydrogen bonds increases more slowly below the SIP. Moreover, the strengths and lifetimes of the hydrogen bonds also rise dramatically below the SIP, causing the internal-energy term to dominate the excess surface free energy. Thus, the SIP in the surface tension of supercooled TIP4P-2005 water is associated with an increase in the strengths and lifetimes of hydrogen bonds, along with a decrease in the formation rate (#/K) of new hydrogen bonds.
Observation of Renner–Teller and predissociation coupled vibronic intensity borrowing in dissociative electron attachment to OCS
Authors: Kundu Narayan , Nandi Dhananjay 
Published: March 2024

We use a time-of-flight-based velocity map imaging method to look into the dissociative electron attachment to a linear OCS molecule at electron beam energies ranging from 4.5 to 8.5 eV. The conical time-gated wedge slice imaging method is utilized to extract fragments’ slice images, kinetic energy (KE), and angular distributions, which provide a complete kinematic understanding of this experiment on the dissociative electron attachment process. We observe that the formation of S− is relatively higher than the O− product. Three distinct dissociative KE bands of S−/OCS have been observed for the 5.0 and 6.5 eV resonance positions. We notice a prominent rovibrationally coupled bimodality for each KE band in the variation of the most probable KE values. When the electron energy is changed from 5.5 to 6.0 eV, we observed vibronic intensity borrowing in the highest momentum band of S− via the Σ → Π symmetric dipole-forbidden transitions within the 1.5 eV energy gap. Multiple peaks in the angular distributions of S− and their modeling indicate the presence of Renner–Teller vibronic splitting. Using Q-Chem’s implemented complex absorbing potential-equation of motion-electron affinity coupled cluster singles and doubles aug-cc-pVDZ+4s3p level of multireference-based electronic structure theory, we confirm the presence of OCS temporary negative ion bending vibrations and Renner–Teller vibronic splittings for the Π symmetric states. Additionally, we notice the presence of a non-radiative predissociation continuum (bringing down the rotational spectrum) and speed-dependent angular anisotropy in the S− fragmentation. Our findings at the resonance of OCS at 6.5 eV closely align with the prediction of vibronic intensity borrowing by Orlandi and Siebrand [J. Chem. Phys. 58, 4513 (1973)].
Dynamics of polylactic acid under ultrafine nanoconfinement: The collective interface effect and the spatial gradient
Authors: Cheng Shiwang , Kogut David , Zheng Juncheng , Patil Shalin , Yang Fuming , Lu Weiyi 
Published: March 2024

Polymers under nanoconfinement can exhibit large alterations in dynamics from their bulk values due to an interface effect. However, understanding the interface effect remains a challenge, especially in the ultrafine nanoconfinement region. In this work, we prepare new geometries with ultrafine nanoconfinement ∼10nm through controlled distributions of the crystalline phases and the amorphous phases of a model semi-crystalline polymer, i.e., the polylactic acid. The broadband dielectric spectroscopy measurements show that ultrafine nanoconfinement leads to a large elevation in the glass transition temperature and a strong increment in the polymer fragility index. Moreover, new relaxation time profile analyses demonstrate a spatial gradient that can be well described by either a single-exponential decay or a double-exponential decay functional form near the middle of the film with a collective interface effect. However, the dynamics at the 1–2 nm vicinity of the interface exhibit a power-law decay that is different from the single-exponential decay or double-exponential decay functional forms as predicted by theories. Thus, these results call for further investigations of the interface effect on polymer dynamics, especially for interfaces with perturbed chain packing.
Signatures of nearly compensated magnetism and spin glass behavior in highly frustrated β-Mn-type Mn50Fe25+xAl25−x Heusler alloys
Authors: Khorwal Abhinav Kumar , Saha Sujoy , Lukoyanov Alexey V. , Patra Ajit K. 
Published: March 2024

The present study examines the effect of Fe/Al concentration on the structural and magnetic properties of Mn-rich Mn50Fe25+xAl25−x (x = 5, 10, 15) Heusler alloys through x-ray diffraction, temperature- and field-dependent DC magnetization, thermoremanent magnetization, magnetic memory effect, AC susceptibility measurements, and DFT calculations. The samples crystallize in a cubic β-Mn structure. The trend shows a reduction in lattice parameters (unit cell volume) with the increasing Fe proportion. These alloys exhibit strong antiferromagnetic interactions with large frustration parameters, indicating the presence of competing magnetic interactions. The DC magnetization data reveal spin glass-like features with a peak at spin glass freezing temperature (Tf). The observation of bifurcation in temperature-dependent zero-field-cooled and field-cooled magnetization curves, exponential dependence of the temperature variation of remanence and coercivity, magnetic relaxation, and magnetic memory effect below Tf support the spin-glass character of these alloys. The frequency dependence of Tf is also examined in the context of dynamic scaling laws, such as the Vogel–Fulcher law and critical slowing down model, which further supports the presence of spin glass behavior. In the theoretical DFT calculations, the electronic structure is found to be metallic and similar for both spin projections. Moreover, the antiferromagnetic arrangement of the magnetic moments, in line with the experimental observations, is stabilized by exchange interactions, resulting in an almost compensated total magnetic moment of 0.02–0.38 µB/f.u. This is probably caused by the frustrated structure and non-stoichiometric compositions of Mn50Fe25+xAl25−x.
Acceptance and use of condoms among school-aged young people in Australia
Authors: Power Jennifer , Kauer Sylvia , Fisher Christopher , Bourne Adam 
Published: March 2024

Background Despite availability of vaccines or medical prophylaxis for some sexually transmissible infections (STIs), promoting condom use remains an important public health strategy for the prevention of STIs. Recent research shows that regular condom use among young people in Australia has declined over the past decade, while the rate of common STIs has increased. Method In this paper, we report findings from a large survey of school-aged young people in Australia (14–18 years old) in which we looked at the association between condom use and positive feelings about sex, beliefs about social acceptability of condoms and confidence talking with partners about sex and condoms. Results Communication and relational factors supported more consistent condom use. Participants were more likely to regularly use condoms if they discussed condom use with a sexual partner, perceived condom use to be easy (a measure that included perceived ease of discussing condoms with a partner) and perceived condom use to offer social or relational benefits, including perceiving condom use as a demonstration of care for a partner. Young men were more likely to report positive feelings about sex and regular condom use than young women. Young women were less likely than young men or trans and non-binary young people to report regular condom use. Conclusions The study shows the importance of supporting young people to build confidence expressing sexual needs and wants with partners. Public health approaches to STI prevention need to consider condom promotion in the context of young people’s contemporary sexual, gendered and relationships cultures.
‘Every strategy needs to be contributing to erasing the stigma’: Māori and Pacific young people talk about overcoming barriers to testing for sexually transmitted infections
Authors: Rose Sally B. , Dunlop Abby , Gardiner Tracey , Cole Marama , Garrett Susan M. , McKinlay Eileen M. 
Published: March 2024

Background Māori and Pacific young people are disproportionately impacted by sexually transmitted infections (STIs). Access to STI screening is important to reduce transmission and reproductive health complications. Methods Between November 2022 and May 2023, we held four wānanga (workshops) with Māori and Pacific participants (15–24 years old) to find out what barriers they encounter to STI testing, and hear their ideas about how to overcome these. Participants were recruited via youth-focused community organisations in the Wellington region of Aotearoa New Zealand. Inductive thematic analysis was used to understand data generated from discussions, drawing on Māori and Pacific models of wellbeing to frame themes. Results Thirty-eight participants were involved in the wānanga. Barriers to STI testing related to five themes: (1) differences in cultural values and expression; (2) family/friends; (3) educational gaps; (4) psychological factors; and (5) structural obstacles. Suggested strategies to improve access to sexual health care included the need for free, flexible services, education and health promotion activities to reach young people in their spaces (e.g. church, marae, social media). Participants stressed the need for approaches to be community-based, delivered by trusted individuals using culturally appropriate messages, and saw participation in STI testing as beneficial for whānau/family and communities. Conclusions To improve access to STI testing, participants described the need for free services, together with education and health promotion to improve inter-generational sexual health knowledge. Reframing messages around STIs to align with Māori and Pacific models of wellbeing was identified as a way to normalise conversations, in turn reducing the stigma surrounding STI testing.
A DFT approach to explore the structural, optoelectronic, mechanical, and thermoelectric attributes of lead-free RbInX3 (X = I, Br, Cl) halide perovskites for renewable energy applications
Authors: Murtaza Hudabia , Ain Quratul , Munir Junaid , Ghaithan Hamid M , Ahmed Abdullah Ahmed Ali , Aldwayyan Abdullah S , H Qaid Saif M 
Published: March 2024

Abstract
Halide perovskites are significant due to their versatility and high performance in optoelectronics and green technologies. This paper thoroughly investigates the structural, elastic, optoelectronic and transport characteristics of RbInX3 (X = I, Br, Cl) perovskites using density functional theory (DFT) embedded in Wein2K. Modified Becke Johnson as an exchange correlation potential is used to evaluate the physical characteristics. Structural stability is achieved with the tolerance factor and octahedral tilting along with the optimization curves. A metallic character is detected in RbInI3. However, the replacement of I with Br and Cl atoms results in an indirect band gap of 0.9 eV and 1.95 eV at (L-X) symmetry points, respectively. The elastic constants are utilized to determine the elastic parameters that ensure the structural stability of perovskites. Cauchy pressure and Poisson’s ratio indicate the ductile nature of all studied phases. The thermal behavior is evaluated through the computation of Debye temperature. Furthermore, an insight into the material’s interaction with electromagnetic radiation is accessed through the optical parameters. A high absorption at 1.49 eV for RbInI3, 1.65 for RbInBr3 and 2.57 for RbInCl3 show their potential for light emitting devices. The semi-classical Boltzmann theory is employed to compute thermoelectric properties, which show RbInI3, RbInBr3 and RbInCl3 possess high electrical conductivities of 3.068

×

10

19

S m–1, 1.88

×

10

19

S m–1 and 1.76

×

10

19

S m–1 at 1200 K, respectively. The ZT value for RbInBr3 is 0.74 and RbInCl3 is 0.73, while RbInI3 exhibit the lowest ZT of 0.04 at 1200 K. The examined characteristics indicate that RbInBr3 and RbInCl3 possess promising potential for renewable energy applications.
Bound states of relativistic spinless particles in a mix of circularly symmetric vector and scalar harmonic oscillators
Authors: Mendrot V B , de Castro A S , Alberto P 
Published: March 2024

Abstract
We study the dynamics of relativistic spinless particles moving in a plane when there is circular symmetry. The general formalism for solving the Klein–Gordon equation in cylindrical coordinates for such systems is presented, as well as the conserved observables and the corresponding quantum numbers. We look for bound solutions of the corresponding Klein–Gordon equation when one has vector and scalar circularly symmetric harmonic oscillator potentials. Both positive and negative bound solutions are considered when there is either equal vector and scalar potentials or symmetric vector and scalar potentials, and it is shown how both cases are related through charge conjugation. We compute the non-relativistic limit for those cases, and show that for symmetric scalar and vector potentials the limit does not exist in the first order of an harmonic oscillator frequency, recovering a known result from the Dirac equation with the same kind of potentials.
Voltage-tunable graphene-InP schottky photodetector with enhanced responsivity using plasmonic waveguide integration
Authors: Vaghef-Koodehi Arash , Nikoufard Mahmoud , Rostami-Khomami Ali 
Published: March 2024

Abstract
In this work, we propose and theoretically investigate a novel side-illuminated graphene Schottky photodetector (SIGS-PD) integrated on an InP waveguide platform suitable for the telecommunication wavelength of 1.55 μm. Bilayer graphene is positioned to absorb the transverse magnetic (TM) mode, with an InP substrate forming a Schottky junction to enable electrical connectivity and carrier separation. Through electrostatic gating, the graphene Fermi level is actively tuned to reach an epsilon-near-zero condition of 0.51 eV, transitioning the optical properties from dielectric to metallic. This supports reconfigurable plasmonic modes confined within the subwavelength graphene layer, interacting strongly with the TM optical mode. Responsivity of TM mode is enhanced 10 × TE mode reaching 1.24 A W−1 at the epsilon-near-zero point for the wavelength of 1.55 μm due to discontinuity and localization of the perpendicular electric field. The maximum responsivity is achieved at reverse bias of 4.5 V for device lengths under 4 μm. Dark current is suppressed to 10−15 A by the rectifying Schottky junction. An internal specific detectivity of 9.6 × 1012 Jones is predicted along with >25 GHz bandwidth, exploiting combined benefits of plasmonic enhancement and electrical transport control in the hybrid graphene-InP platform. The voltage-tunability of the graphene optical properties provides a pathway to dynamically optimize device performance. This work demonstrates a route towards high-responsivity and high-speed graphene photodetectors seamlessly integrated with photonic integrated circuits.
Molecular docking studies, structural analysis, biological studies, and synthesis of certain novel Schiff base from benzohydrazide derivate
Authors: Gosu Nageswara Reddy , C Hazarathaiah Yadav , K Ramakrishna Reddy , Losetty Venkatramana , Sampath Sridhar 
Published: March 2024

Abstract
The research described involves the synthesis and characterization of a new benzohydrazide based Schiff base compound namely 4-methyl-N′-(2,4,5-trimethoxybenzylidene) benzohydrazide (HL). The compound was synthesized by condensing a primary amine and an aldehyde functional group. The characterization of the compound was carried out using various spectroscopic techniques, including elemental analysis, Ultraviolet spectroscopy, nuclear magnetic resonance spectroscopy, and infrared spectroscopy. These techniques helped confirm the excellent quality of the synthesized molecules. In addition to the characterization, the Schiff base compound was subjected to docking studies and biological studies. The antibacterial activity of the compound was tested against three strains of bacteria, namely E. faecalis, B. subtills, and E. coli. The results of these tests provided information on the compound effectiveness against these bacterial strains. Furthermore, docking studies was performed to assess the interaction between the synthesized compound and three target enzymes like GlcN-6-p synthase, DNA polymerase, and EGFR tyrosine kinase. Docking studies are computational simulations that provide insights into the binding interactions between Schiff base ligand and target proteins. In this case, the docking studies helped understand the potential mechanisms of action of the synthesized compound by calculating binding constants and the number of binding modes. The biological activity studies revealed interesting fragmentation patterns, which could be further investigated to understand the compound modes of action. Moreover, the docking studies evaluated the compound’s potential as a drug candidate by assessing its binding interactions with the target enzymes. The present study suggests that the synthesized benzohydrazide based Schiff base compound exhibits potential antibacterial activity and shows promising binding interactions with the target protein/enzymes. This information is valuable for designing and developing more potent compounds in the future.