bluuebunny/crossref_metadata_2025_split huggingface dataset:
Young people as a political subject in the context of environmental governance
Authors: Rodela Romina , Roumeliotis Filip 
Published: July 2024

AbstractThe discourse on environmental challenges has evolved significantly in recent years, with climate change emerging as a central global concern. This transformation has been heavily influenced by the last wave of youth-led social movements, notably the Fridays for Future movement, who have mobilized young people at a global scale contributing at a shift in public discourse on the topic of climate action. However, despite the impact of the newly emerged youth-led movements it is still rather unclear if and where has youth gained recognition as a group with special interests within environmental policy and governance. In this study we report on a research were we investigated the positioning of youth in contemporary environmental governance, and propose a theoretical perspective to understand how the subject category of “youth” is constructed in public discourse and its implications for political recognition. We study the progressive emergence of Greta Thunberg as a voice for a generation of youth climate activists and undertake a document analysis of selected material generated in relation to selected international political events. By addressing questions of recognition, discourse structure, and legitimacy, this research aims to shed light on the nuanced dynamics shaping the role of youth in environmental policy and governance.
A cryogenic forced oscillation apparatus to measure anelasticity of ice
Authors: Yamauchi Hatsuki , McCarthy Christine , Leeman John R. , Holtzman Benjamin K. 
Published: July 2024

We have developed a new cryogenic uni-axial forced oscillation apparatus to measure the anelastic behavior of ice by adapting the design of a previous high-precision apparatus for use in low-temperature (&lt;0 °C) conditions. With this new apparatus, Young’s modulus and attenuation can be measured over a broad frequency range from 10−4 to 10 Hz. We have performed calibration tests with standard materials (steel spring, stainless steel, and acrylic samples) under various conditions to assess the apparatus properties and correct the effects on the obtained raw data. Young’s modulus and attenuation for an acrylic sample after all of the data corrections show good agreement with previously published values, demonstrating the validity of the data corrections and reliability of the obtained data. We further obtained a preliminary dataset of Young’s modulus and attenuation for an ice polycrystalline sample under small median stress and small stress amplitude. The anelastic response was not strain amplitude-dependent, that is, the response is linear. Moreover, the attenuation data are consistent with the data measured for other polycrystalline materials under similarly small stress conditions in terms of the Maxwell frequency scaling, which is known as a scaling law applicable to linear anelasticity induced by the diffusionally accommodated grain boundary sliding mechanism. Although there is still room for improving the control of testing conditions, we show that the new forced oscillation apparatus is capable of systematic studies on the anelastic properties of ice, the subject of future studies.
Charge exchange recombination spectroscopy on the alkali beam of Wendelstein 7-X
Authors: Csillag B. G. , Anda G. , Cseh G. , Dunai D. , Ford O. P. , Flom E. , Gradic D. , Henke F. , Krychowiak M. , Nagy D. , Otte M. , Réfy D. I. , Tőkési K. , Vécsei M. , Zoletnik S. ,   the W7-X Team
Published: July 2024

Measurements of ion temperature profiles are required to assess the energy and particle transport processes in the Wendelstein 7-X stellarator. This device is equipped with a diagnostic alkali beam, which can be utilized to determine local impurity temperatures and densities by Charge Exchange Recombination Spectroscopy (CXRS). It could provide such profiles in the edge plasma, where other diagnostics are less efficient. With this contribution, first results of CXRS measurements on the sodium beam from the scientific operation phase OP2.1 are presented. The spectroscopic system was in commissioning phase lacking some of the final optical components. Thus, the aim of the diagnostics during this campaign was to explore the measurement capabilities. Based on the processed spectra, the prospects of C5+ and C6+ ion temperature and concentration measurements are discussed. The results indicate that with the final optical setup under installation, the diagnostics could provide ion temperature profiles in the edge with 3 mm radial resolution and at least 1 s temporal resolution.
Individual tree detection and classification from RGB satellite imagery with applications to wildfire fuel mapping and exposure assessments
Authors: Bennett L. , Yu Z. , Wasowski R. , Selland S. , Otway S. , Boisvert J. 
Published: July 2024

Background Wildfire fuels are commonly mapped via manual interpretation of aerial photos. Alternatively, RGB satellite imagery offers data across large spatial extents. A method of individual tree detection and classification is developed with implications to fuel mapping and community wildfire exposure assessments. Methods Convolutional neural networks are trained using a novel generational training process to detect trees in 0.50 m/px RGB imagery collected in Rocky Mountain and Boreal natural regions in Alberta, Canada by Pleiades-1 and WorldView-2 satellites. The workflow classifies detected trees as ‘green-in-winter’/‘brown-in-winter’, a proxy for coniferous/deciduous, respectively. Key results A k-fold testing procedure compares algorithm detections to manual tree identification densities reaching an R2 of 0.82. The generational training process increased achieved R2 by 0.23. To assess classification accuracy, satellite detections are compared to manual annotations of 2 cm/px drone imagery resulting in average F1 scores of 0.85 and 0.82 for coniferous and deciduous trees respectively. The use of model outputs in tree density mapping and community-scale wildfire exposure assessments is demonstrated. Conclusion & Implications The proposed workflow automates fine-scale overstorey tree mapping anywhere seasonal (winter and summer) 0.50 m/px RGB satellite imagery exists. Further development could enable the extraction of additional properties to inform a more complete fuel map.
Numerical relativity multimodal waveforms using absorbing boundary conditions
Authors: Buchman Luisa T , Duez Matthew D , Morales Marlo , Scheel Mark A , Kostersitz Tim M , Evans Andrew M , Mitman Keefe 
Published: July 2024

Abstract
Errors due to imperfect boundary conditions in numerical relativity simulations of binary black holes (BBHs) can produce unphysical reflections of gravitational waves which compromise the accuracy of waveform predictions, especially for subdominant modes. A system of higher order absorbing boundary conditions which greatly reduces this problem was introduced in earlier work (Buchman and Sarbach 2006 Class. Quantum Grav.
23 6709). In this paper, we devise two new implementations of this boundary condition system in the Spectral Einstein Code (SpEC), and test them in both linear multipolar gravitational wave and inspiralling mass ratio 7:1 BBH simulations. One of our implementations in particular is shown to be extremely robust and to produce accuracy superior to the standard freezing-Ψ0 boundary condition usually used by SpEC.
Ab initio study of helium behavior near stacking faults in 3C-SiC
Authors: Wang Rongshan , Zhang Limin , Jiang Weilin , Daghbouj Nabil , Polcar Tomas , Ejaz Ahsan , Wang Zhiqiang , Chen Liang , Wang Tieshan 
Published: July 2024

Abstract
First-principles calculations are used to investigate the effects of stacking faults (SFs) on helium trapping and diffusion in cubic silicon carbon (3C-SiC). Both extrinsic and intrinsic SFs in 3C-SiC create a hexagonal stacking sequence. The hexagonal structure is found to be a strong sink of a helium interstitial. Compared to perfect 3C-SiC, the energy barriers for helium migration near the SFs increase significantly, leading to predominant helium diffusion between the SFs in two dimensions. This facilitates the migration of helium towards interface traps, as confirmed by previous experimental reports on the nanocrystalline 3C-SiC containing a high density of SFs. This study also reveals that the formation of helium interstitial clusters near the SFs is not energetically favored. The findings from this study enhance our comprehension of helium behavior in faulted 3C-SiC, offering valuable insights for the design of helium-tolerant SiC materials intended for reactor applications.
Hydrodynamics of a disk in a thin film of weakly nematic fluid subject to linear friction
Authors: Daddi-Moussa-Ider Abdallah , Tjhung Elsen , Richter Thomas , Menzel Andreas M 
Published: July 2024

Abstract
To make progress towards the development of a theory on the motion of inclusions in thin structured films and membranes, we here consider as an initial step a circular disk in a two-dimensional, uniaxially anisotropic fluid layer. We assume overdamped dynamics, incompressibility of the fluid, and global alignment of the axis of anisotropy. Motion within this layer is affected by additional linear friction with the environment, for instance, a supporting substrate. We investigate the induced flows in the fluid when the disk is translated parallel or perpendicular to the direction of anisotropy. Moreover, expressions for corresponding mobilities and resistance coefficients of the disk are derived. Our results are obtained within the framework of a perturbative expansion in the parameters that quantify the anisotropy of the fluid. Good agreement is found for moderate anisotropy when compared to associated results from finite-element simulations. At pronounced anisotropy, the induced flow fields are still predicted qualitatively correctly by the perturbative theory, although quantitative deviations arise. We hope to stimulate with our investigations corresponding experimental analyses, for example, concerning fluid flows in anisotropic thin films on uniaxially rubbed supporting substrates.
Demonstrating beat phenomenon and Lissajous figures with hard disk drive voice-coil motors
Authors: Hu Lian 
Published: July 2024

Abstract
Voice coil motors (VCMs) in mechanical hard disk drives can be used as the adjustable-electric tuning fork driven by alternating signals due to their unique structure and movement. The VCM component is modified to pull the laser or mirror for phase-adjustable simple harmonic motion (SHM). Lissajous experiments using the traditional tuning fork for active vibration can be achieved by VCMs with the help of a laser and a scrollable phosphorescent screen. The demonstrations of beat and Lissajous figures with the double oscillating mirrors method are analysed. The VCM can not only drive the mirror but also drive the laser or another VCM component. Based on this carrying capacity, the demonstration method of a single oscillating mirror has been proposed. Furthermore, one VCM can support another with a laser, which will exhibit the composition of two rotary SHMs more intuitively. The new method is beneficial for students to understand and practice the composition of SHMs from a new perspective.
Unpacking the factors that influence secondary students’ attitudes towards physics in nine different countries - a cross-cultural analysis
Authors: Pongsophon Pongprapan 
Published: July 2024

Abstract
It is crucial to comprehend the factors that affect attitudes towards physics to improve academic performance in the subject. This research aims to identify significant predictors of these attitudes by analysing the Trends in International Mathematics and Science Study Advanced 2015 data from nine countries: the USA, Italy, Lebanon, Norway, Portugal, Russia, Slovenia, Sweden, and France. The study employs multiple regression analyses to examine the influence of predictive variables on students’ attitudes toward physics, taking into account weighting features a large-scale survey. The findings suggest that there are significant differences across cultures. In all the countries surveyed, female students appear to have a less favourable attitude toward physics than male students, making gender a significant factor. In most countries, students who spend more time on physics homework have a more positive attitude, highlighting the importance of outside-of-class engagement. The perception of engaging teaching and the value that students place on physics are solid and positive determinants of attitudes, emphasizing the role of instructional quality and relevance of the subject matter. These findings provide a better understanding of how different factors contribute to students’ attitudes toward physics and can help design targeted educational interventions.
Extracting actigraphy-based walking features with structured functional principal components
Authors: Werkmann Verena , Glynn Nancy W , Harezlak Jaroslaw 
Published: July 2024

Abstract

Objective. We extract walking features from raw accelerometry data while accounting for varying cadence and commonality of features among subjects. Walking is the most performed type of physical activity. Thus, we explore if an individual’s physical health is related to these walking features. Approach. We use data collected using ActiGraph GT3X+ devices (sampling rate = 80 Hz) as part of the developmental epidemiologic cohort study, I = 48, age =

78.7
±
5.7

years, 45.8% women. We apply structured functional principal component analysis (SFPCA) to extract features from walking signals on both, the subject-specific and the subject-spectrum-specific level of a fast-paced 400 m walk, an indicator of aerobic fitness in older adults. We also use the subject-specific level feature scores to study their associations with age and physical performance measures. Specifically, we transform the raw data into the frequency domain by applying local Fast Fourier Transform to obtain the walking spectra. SFPCA decomposes these spectra into easily interpretable walking features expressed as cadence and acceleration, which can be related to physical performance. Main results. We found that five subject-specific and 19 subject-spectrum-specific level features explained more than 85% of their respective level variation, thus significantly reducing the complexity of the data. Our results show that 54% of the total data variation arises at the subject-specific and 46% at the subject-spectrum-specific level. Moreover, we found that higher acceleration magnitude at the cadence was associated with younger age, lower BMI, faster average cadence and higher short physical performance battery scores. Lower acceleration magnitude at the cadence and higher acceleration magnitude at cadence multiples 2.5 and 3.5 are related to older age and higher blood pressure. Significance. SFPCA extracted subject-specific level empirical walking features which were meaningfully associated with several health indicators and younger age. Thus, an individual’s walking pattern could shed light on subclinical stages of somatic diseases.
Study of atoms and multiply charged ions features in the nanosecond laser produced Mo plasma in vacuum using optical emission spectroscopy and time-of-flight electrostatic energy analyzer
Authors: Li Yu , Wu Ding , Wang Xinyue , Hu Xiaohan , Xu Ke , Wu Huace , Hai Ran , Li Cong , Feng Chunlei , Ding Hongbin 
Published: July 2024

Abstract
The species including atoms and multiply charged ions in the laser produced molybdenum (Mo) plasma are investigated in this work using optical emission spectroscopy and time-of-flight electrostatic energy analyzer (TOF-EEA). Nanosecond laser (5 ns, 1064 nm,) pulses were focused on the Mo target surface with a spot size of 0.4 mm2, energy of ∼150 mJ/pulse (corresponding to a power density of ∼7.5 GW cm−2) to generate the Mo plasma in vacuum environment. Time-resolved spectral analysis was carried out to investigate the temporal evolution of continuous background, atomic, and monovalent ionic spectral signals. The Saha–Boltzmann method is applied for spectral fitting, providing insight into the temporal evolution of electron temperature (T
e) and electron density (n
e). Over the time from 40 ns to 500 ns, the T
e decreases from 3.6 eV to 0.52 eV, and the n
e decreases from 2.5 × 1020 cm−3–1.0 × 1015 cm−3. Linear fitting extrapolation predicts the T
e and n
e could be even up to 6.3 eV and 2.5 × 1022 cm−3, respectively, at the early stage of 10 ns. This indicates the generation of multiply charged ions during the laser ablation process. The multiply charged ions up to 6 charge states were observed by the TOF-EEA and the energy distributions for the different charged ions were also obtained. It was found the ion kinetic energy is positively related to the number of charge state indicates the existence of acceleration electric field. The equivalent accelerating potential is determined as approximately 570 V at the current laser power density. This research provides a significant reference for the establishment of models for laser ablation plasmas and a profound understanding of the underlying physical processes.
Photon discerner: adaptive quantum optical sensing near the shot noise limit
Authors: Bao Fanglin , Bauer Leif , López Adrián E Rubio , Yang Ziyi , Wang Xueji , Jacob Zubin 
Published: July 2024

Abstract
Photon statistics of an optical field can be used for quantum optical sensing in low light level scenarios free of bulky optical components. However, photon-number-resolving detection to unravel the photon statistics is challenging. Here, we propose a novel detection approach, that we call ‘photon discerning’, which uses adaptive photon thresholding for photon statistical estimation without recording exact photon numbers. Our photon discerner is motivated by the field of neural networks where tunable thresholds have proven efficient for information extraction in machine learning tasks. The photon discerner maximizes Fisher information per photon by iteratively choosing the optimal threshold in real-time to approach the shot noise limit. Our proposed scheme of adaptive photon thresholding leads to unique remote-sensing applications of quantum degree of linear polarization camera and quantum LiDAR. We investigate optimal thresholds and show that the optimal photon threshold can be counter-intuitive (not equal to 1) even for weak signals (mean photon number much less than 1), due to the photon bunching effect. We also put forth a superconducting nanowire realization of the photon discerner which can be experimentally implemented in the near-term. We show that the adaptivity of our photon discerner enables it to beat realistic photon-number-resolving detectors with limited photon-number resolution in certain applications. Our work suggests a new class of detectors for information-theory driven, compact, and learning-based quantum optical sensing.
Conceptional proposal of a microwave-only quantum magnetic head by phase-induced tunneling magnetoresistance effects and of a 3-dimensional multilayer platter
Authors: Fujii Genji 
Published: July 2024

Abstract
Tunneling magnetoresistance effects result in a high-performance magnetic head, enabling a high magnetic domain density in a platter. This conventional method of using magnetic flux to read or write is close to the magnetic domain density limit. Herein, we propose a conceptional method for developing a magnetic head by controlling phase-induced tunneling magnetoresistance effects. The developed magnetic head can be read out in units of 1 qubit. However, because recording data per BEC qubit is difficult due to thermal fluctuations, we evaluated the robustness of the method and concluded that it is robust to bit flips. Our method does not use a magnetic field for reading or writing, further suggesting that one may use a microwave instead. This is a distinguishing feature, allowing further integration of the magnetic domain density in a platter.
Light-field modulation and optimization near metal nanostructures utilizing spatial light modulators
Authors: Cao 曹 Zini 子倪 , Lin 林 Hai 海 , Cheng 程 Yuqing 宇清 , Xu 徐 Yixuan 艺轩 , Gong 龚 Qihuang 旗煌 , Lü 吕 Guowei 国伟 
Published: July 2024

Abstract
Plasmonic modes within metal nanostructures play a pivotal role in various nanophotonic applications. However, a significant challenge arises from the fixed shapes of nanostructures post-fabrication, resulting in limited modes under ordinary illumination. A promising solution lies in far-field control facilitated by spatial light modulators (SLMs), which enable on-site, real-time, and non-destructive manipulation of plasmon excitation. Through the robust modulation of the incident light using SLMs, this approach enables the generation, optimization, and dynamic control of surface plasmon polariton (SPP) and localized surface plasmon (LSP) modes. The versatility of this technique introduces a rich array of tunable degrees of freedom to plasmon-enhanced spectroscopy, offering novel approaches for signal optimization and functional expansion in this field. This paper provides a comprehensive review of the generation and modulation of SPP and LSP modes through far-field control with SLMs and highlights the diverse applications of this optical technology in plasmon-enhanced spectroscopy.
Warm inflation triggered by entropies of some recent dark energy models within
gravity
Authors: Saleem Rabia , Rasool Muhammad Hamza , Aslam M. Israr , Shahid Iqra 
Published: July 2024

Abstract
This manuscript aims to study cosmic warm inflation (WI) in the framework of

- gravity, where Q represents the nonmetricity (NM) scalar. To accomplish this task, we introduce the Tsallis, Renyi, and Barrow holographic dark energy (HDE) entropies into the standard Friedmann equations. Utilizing the slow-roll (SR) approximation, we find exact analytic solutions for the inflaton field, the effective potential necessary to produce inflation, and the scale factor for both low- and high-dissipative regimes. We calculate key parameters, including SR parameters, the number of e-folds, the scalar spectral index and its running, and finally tensor-to-scalar ratio to assess the accuracy of the chosen DE models in light of the published observational data. The allowed ranges of the involved free parameters are found from the limits on inflationary observables imposed by the Planck data. It is concluded that the obtained results are consistent with proposed theoretical predictions up to the

confidence level.
Tidal force effects and bound orbits in null naked singularity spacetime
Authors: Madan Siddharth , Bambhaniya Parth 
Published: July 2024

Abstract
Naked singularities form during the gravitational collapse of inhomogeneous matter clouds. The final nature of the singularity depends on the initial conditions of the matter properties and types of matter profiles. These naked singularities can also be divided into two types: null-like and timelike singularities. The spacelike singularity of the Schwarzschild black hole can be distinguished from the null and timelike naked singularity spacetimes. In light of this, we investigate the precession of timelike bound orbits in the null naked singularity spacetime, as well as tidal force effects and geodesic deviation features. As a result, we find that the orbital precession of the timelike bound orbits in null naked singularity spacetime could be distinguished from the Schwarzschild precession case. The radial component of the tidal force has an intriguing profile, whereas the angular component has a profile that is comparable to that of a Schwarzschild black hole scenario. The geodesic deviation equation is then solved numerically, yielding results that resemble Schwarzschild black holes. These characteristic features can then be used to discern among these singularities.