bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the importance of parallel magnetic-field fluctuations for electromagnetic instabilities in STEP
Authors: Kennedy D. , Roach C.M. , Giacomin M. , Ivanov P.G. , Adkins T. , Sheffield F. , Görler T. , Bokshi A. , Dickinson D. , Dudding H.G. , Patel B.S. 
Published: June 2024

Abstract
This paper discusses the importance of parallel perturbations of the magnetic-field in gyrokinetic simulations of electromagnetic instabilities and turbulence at mid-radius in the burning plasma phase of the conceptual high-β, reactor-scale, tight-aspect-ratio tokamak STEP. Previous studies have revealed the presence of unstable hybrid kinetic ballooning modes (hKBMs) and subdominant microtearing modes at binormal scales approaching the ion Larmor radius. In this STEP plasma it was found that the hKBM requires the inclusion of parallel magnetic-field perturbations to be linearly unstable. Here, the extent to which the inclusion of fluctuations in the parallel magnetic-field can be relaxed is explored through gyrokinetic simulations. In particular, the frequently used MHD approximation (dropping

δ

B

∥

and setting the

∇
B

drift frequency equal to the curvature drift frequency) is discussed and simulations explore whether this approximation is useful for modelling STEP plasmas. It is shown that the MHD approximation can reproduce some of the linear properties of the full STEP gyrokinetic system, but is too stable at low ky
and nonlinear simulations using the MHD approximation result in very different transport states. It is demonstrated that the MHD approximation is challenged by the high

β

′

values in STEP, and that the approximation improves considerably at lower

β

′

. Furthermore, it is shown that the sensitivity of STEP to

δ

B

∥

fluctuations is primarily because the plasma sits close to marginality and it is shown that in slightly more strongly driven conditions the hKBM is unstable without

δ

B

∥

.

Crucially, it is demonstrated that the state of large transport typically predicted by local electromagnetic gyrokinetic simulations of STEP plasmas is not solely due to

δ

B

∥

physics.
Observations and emission constraints of trichlorofluoromethane (CFC-11) in southeastern China: first-year results from a new AGAGE station
Authors: Chen Yuyang , Yao Bo , Wu Jing , Yang Honglong , Ding Ao , Liu Song , Li Xicheng , O’Doherty Simon , Li Juan , Li Yali , Yu Haibo , Wang Wenli , Chen Liqu , Yang Xin , Fu Tzung-May , Shen Huizhong , Ye Jianhuai , Wang Chen , Zhu Lei 
Published: June 2024

Abstract
The recovery of the ozone layer relies on decreasing atmospheric mixing ratios of ozone-depleting substances (ODSs), including chlorofluorocarbons (CFCs). A significant decline in the mixing ratio of trichlorofluoromethane (CFC-11 or

CCl
3

F

), the second most abundant CFC, has been observed since the mid-1990s. However, a slowdown in the decline after 2012 indicates a rise in emissions, particularly in Eastern Asia. Ground-based observations are lacking in southeastern China, limiting a thorough evaluation of CFC-11 levels and emissions in this region. A new Advanced Global Atmospheric Gases Experiment background station was established at Xichong (XCG), Shenzhen, China, to provide high-frequency continuous in situ observations. The annual mean CFC-11 mixing ratio, recorded from May 2022 to April 2023, is 221.64 ± 2.29 ppt. When compared with a monthly (MHD) or daily (MLO) observation, this value is found to be 0.45% to 5.36% higher than the northern hemispheric background. With the inverse modeling and interspecies correlation method, we estimate CFC-11 emissions in southeastern China between 1.23 ± 0.25 Gg yr−1 and 1.58 ± 0.21 Gg yr−1, in line with the bottom-up estimation of 1.50 Gg yr−1. Results indicate that CFC-11 emissions in the Pearl River Delta region have returned to levels before 2010, aligning with regional and global trends. Observations from XCG would compensate for the deficiency of CFC-11 measurements in southeastern China, paving the road for ODS studies in this region and beyond.
Non-Hermitian propagation in equally-spaced waveguide arrays
Authors: Bocanegra-Garay Ivan A , Moya-Cessa Héctor M 
Published: June 2024

Abstract
A non-unitary transformation leading to a Hatano–Nelson problem is performed on an array of equally-spaced optical waveguides. Such transformation produces a non-reciprocal system of waveguides, as the corresponding Hamiltonian becomes non-Hermitian. This may be achieved by judiciously choosing an attenuation (amplification) of the injected (or exciting) field. The non-Hermitian transport induced by such transformation is studied for several cases and closed analytical solutions, not present in the available literature, are straightforwardly obtained. The corresponding non-Hermitian Hamiltonian may represent an open system that interacts with the environment, either loosing to or being provided with energy from the exterior.
Polyvinyl alcohol nanofibrous mat impregnated with ClCNTs/Fe2O3 nanocomposite for absorption of diesel oil in water
Authors: Motlokoa Teboho R , Ngodwana Lonwabo , Maboya Winny K 
Published: June 2024

Abstract
Oil contamination is one of the main sources of water pollution in the world. In this study, a sorption material that showed great promise as an absorbent for diesel oil in aqueous solution was developed. Chlorinated carbon nanotubes (CNTs) previously synthesized using a chemical vapor deposition (CVD) method were loaded with iron oxide nanoparticles via a co-precipitation method. The sorption materials were prepared by embedding ClCNTs/Fe2O3 nanocomposite into a polyvinyl alcohol (PVA) polymer matrix via electrospinning. The PVA mat containing only ClCNTs was also prepared for comparison and the maximum sorption capacity of 9.7 g g−1 was obtained. The optimum concentration of ClCNTs/Fe2O3 nanocomposite that gave uniform, and well-distributed nanofibers was 0.5 wt%. Crosslinking the PVA/ClCNTs/Fe2O3 nanofiber mat with glutaraldehyde (GA) resulted in increased absorption capacity for oil of ∼ 9.4 g g−1 in comparison with an absorption capacity of ∼ 7.6 g g−1 attained with a pure nanofiber mat. The crosslinked nanofiber mat remained stable even after 60 min of oil absorption which proves that crosslinking assisted in increasing the affinity of PVA for oil by reducing the amount of OH groups through acetal formation making PVA less soluble to water. The oil sorption capacity of the prepared materials was not maintained even after two cycles indicating poor reusability.
Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering
Authors: Alibeyoğlu Fatih , Karabudak Filiz , Yeşildal Ruhi , Balcı Arif , Efeoğlu İhsan , Ateş Onur Kazım 
Published: June 2024

Abstract
Despite their extensive use in the automotive and aerospace industries, Mg and Mg alloys, which are light metals, exhibit low fatigue and tensile strength. In this study, transition metal-nitride (TMN) multilayer coatings (Ti+TiN+Ti+TiVN) were coated twice on AZ91 Mg alloy using a Confined Field Unbalanced Magnetron Sputtering (CFUBMS) system to increase fatigue and tensile strength. The structural properties of the films were analyzed by using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometry (EDS) methods, and the mechanical properties were analyzed by rotating bending fatigue and tensile testing machines. Ti+TiN+Ti+TiVN multilayer nitride surface coatings on AZ91 Mg alloys showed a dense and columnar microstructure and according to XRD results (111) was the preferred orientation with the dominant peak. The fatigue limit value of the AZ91 base material was fixed at 60.46 MPa, while it increased to 68.48 MPa after being coated with multilayer nitride. Along with the multilayer nitride coating, the tensile strength increased from 169.98 MPa to 175.43 MPa. As a result, the multilayer hard nitride coating with low surface roughness, which fills the defects, notches, and voids on the surface of the AZ91 base material, increased the fatigue and tensile strength in parallel. Based on the outcomes of the research, the literature has been enriched with an innovative approach through the enhancement of fatigue and tensile strengths by applying a CFUBMS coating to lightweight metals and alloys, such as AZ91, especially in the transportation industry where lightness and dynamic load resistance are essential.
The structural, magnetic, optoelectronic, and mechanical characteristics of NaGeX3 perovskites under pressure for soler-cell applications
Authors: Ovi Istiak Ahmed , Hasan MD Ratul , Apon Imtiaz Ahamed , Zahra Fatema-Tuz 
Published: June 2024

Abstract
This study examines the physical properties of germanium-based halide perovskite through Density Functional Theory (DFT) computations. The physical, optical, mechanical, and magnetic properties of NaGeX3 (X = Cl, Br, and I) were examined with the effects of hydrostatic pressure applied externally. The compounds were subjected to pressure variations ranging from 0 to 5 GPa. The results indicate a decrease in the band gap from the infrared to the visible spectrum. For NaGeCl3, NaGeBr3, and NaGeI3 the band gap decreased from 0.766 eV, 0.497 eV, and 0.400 eV to 0 eV, respectively, indicating the metallic behavior. The mechanical properties of NaGeX3 (X = Cl, Br, and I) demonstrate that for all three compounds, Bulk Modulus (B), Shear Modulus (G), Young’s Modulus (E), Poisson’s ratio (ν), and Pugh’s ratio

B
/
G

all increase with increasing pressure. It demonstrates that all these NaGeX3 (X = Cl, Br, I) compounds are ductile in nature. The compounds are determined to be diamagnetic based on their magnetic property investigation, which reveals no notable changes in behavior up to 5 GPa of rising pressure. To gain a better understanding of the properties of the material when incident light strikes its surface, researchers also looked in at optical absorption, reflectivity, dielectric constants, refractive index, conductivity, and loss functions. Pressure-induced NaGeX3 perovskite compounds, where X = Cl, Br, and I, show an increase in dielectric constant as pressure rises, suggesting a decrease in charge carrier recombination rates and a possibility for higher optoelectronic device efficiency. For all NaGeX3 compounds (where X = Cl, Br, and I), the maximum absorption coefficient peaks are located around 3 eV, indicating that increasing pressure increases optical conductivity. Additionally, they have significantly low reflectance throughout the visible spectrum and very narrow band gap, which indicates significant absorption and the possibility of effective Near-Infrared (NIR) Sensors, photodetector etc applications.
Unleashing the power of artificial neural networks: accurate estimation of monthly averaged daily wind power at Adama wind farm I, Ethiopia
Authors: Woldegiyorgis Tegenu Argaw , Benti Natei Ermias , Habtemicheal Birhanu Asmerom , Jembrie Ashenafi Admasu 
Published: June 2024

Abstract
Wind power plays a vital role in the electricity generation of many countries, including Ethiopia. It serves as a valuable complement to hydropower during the dry season, and its affordability is crucial for the growth of industrial centers. However, accurately estimating wind energy poses significant challenges due to its random nature, severe variability, and dependence on wind speed. Numerous techniques have been employed to tackle this problem, and recent research has shown that Artificial Neural Network (ANN) models excel in prediction accuracy. This study aims to assess the effectiveness of different ANN network types in estimating the monthly average daily wind power at Adama Wind Farm I. The collected data was divided into three sets: training (70%), testing (15%), and validation (15%). Four network types, namely Feedforward Backpropagation (FFBP), Cascade Feedforward Backpropagation (CFBP), Error Backpropagation (EBP), and Levenberg–Marquardt (LR), were utilized with seven input parameters for prediction. The performance of these networks was evaluated using Mean Absolute Percentage Error (MAPE) and R-squared (R2). The EBP network type demonstrated exceptional performance in estimating wind power for all wind turbines in Groups GI, GII, and GIII. Additionally, all proposed network types achieved impressive accuracy levels with MAPE ranging from 0.0119 to 0.0489 and R2 values ranging from 0.982 to 0.9989. These results highlight the high predictive accuracy attained at the study site. Consequently, we can conclude that the ANN model’s network types were highly effective in predicting the monthly averaged daily wind power at Adama Wind Farm I. By leveraging the power of ANN models, this research contributes to improving wind energy estimation, thereby enabling more reliable and efficient utilization of wind resources. The findings of this study have practical implications for the wind energy industry and can guide decision-making processes regarding wind power generation and integration into the energy mix.
The effects of land subsidence and its mitigating measures on shallow groundwater salinization in the low-lying coastal plain of East Japan
Authors: Tsai ChiSan , Ito Yuka , Liu Jiaqi , Tokunaga Tomochika 
Published: June 2024

Abstract
Land subsidence in low-lying coastal regions results from geological and human factors, causing inundation during high tides. Mitigation measures, like pumping stations and ditch systems, aim to address this challenge. However, their impact on groundwater salinity near tidal rivers is understudied. Using a coupled surface-subsurface model, we investigate this issue in the lower Nabaki River region, Shirako Town, Japan. The simulation reveals adverse effects of pumping stations that induce intrusion of saline water from the tidal river into surrounding groundwater. While they are designed to prevent floods, these stations and ditches may inadvertently raise groundwater vulnerability to saltwater contamination. Despite 2D model limitations, it offers valuable insights into coastal groundwater dynamics and salinization. This study provides important information for policymakers and land managers to better understand the consequences of flood mitigation strategies on groundwater quality in vulnerable coastal areas.
Wavelet scattering and multiclass support vector machine (WS_MSVM) for effective fault classification in transformers: a real-time experimental approach
Authors: Shanu Tabish , Mishra Ambarisha 
Published: June 2024

Abstract
The dependable operation of the protective system is affected by residual magnetism and magnetic bias during the activation of the transformer. Challenges arise in distinguishing between inrush current and fault current when the transformer circuit breaker switching angle and remnant flux attain specific values. This situation can lead to a lack of sensitivity or failure in the operation of the transformer protection system. Thus, this paper proposes an effective approach for classifying different faults in transformers (internal and non-internal faults) using wavelet scattering and multiclass support vector machine (MSVM) technique (WS_MSVM). The wavelet scattering method begins by transmitting the data through a sequence of wavelet transforms, nonlinear operations, and averaging processes. This series of operations aims to generate low-variance representations of time series data. Wavelet time scattering produces signal representations that remain unaffected by shifts in the input signal, while still preserving the ability to distinguish between internal and non-internal faults. Internal faults are those occurring within the zones of the current transformer (CT) connected on both sides of the transformer. On the other hand, non-internal faults consist of magnetizing inrush current, sympathetic inrush current, and external faults (faults occurring outside the CT zones). The efficacy of the proposed WS_SVM is evaluated on the real-time experimental results obtained from the differential path of a laboratory transformer. The experimental data generated over one power frequency cycle under diverse operating conditions is employed in MATLAB to assess the effectiveness of the proposed WS_SVM algorithm.
Influence of Graphene/h-BN and SiC/h-BN reinforcing particles on microstructural, mechanical and tribological characteristics of Al7075-based hybrid nanocomposites
Authors: Tile Prashant Suresh , Thomas Benedict 
Published: June 2024

Abstract
Aluminium (Al) based Metal Matrix Composites (MMCs) replaced conventional alloys in numerous sectors like the automotive to aerospace industries. In this investigation, Al7075/Silicon carbide (1 wt%)/Hexagonal-boron nitride (0.5 wt%) and Al7075/Graphene (1 wt%)/Hexagonal-boron nitride (0.5 wt%) hybrid metal matrix nanocomposites (HMMNCs) prepared using an ultrasonic-assisted melt-stirring squeeze casting process. To attain the homogenous mixing of hard ceramic/nanoparticles, reduce the aggregation effect and improve wettability of the reinforcing nanoparticles in the molten slurry. Reinforcement particles mixture (Silicon carbide (1 wt%)/Hexagonal-boron nitride (0.5 wt%) and Graphene (1 wt%)/Hexagonal-boron nitride (0.5 wt%)) have been ball-milled for the duration of 1 to 6 h (hrs). To analyze the morphology of the 1–6 h ball-milled hybrid reinforcing particles mixture was analyzed via scanning electron microscope (SEM). Moreover, microstructural investigation of the Al-based HMMNCs was performed using optical microscopy (OM), field-emission scanning electron microscopy (FE-SEM) and scanning electron microscope (SEM). Also, the dispersal of hybrid reinforcing particles mixture in Al7075-based HMMNCs was examined via SEM-equipped with x-ray mapping analysis. The fabricated Al7075-based HMMNCs are tested for their tensile strength, microhardness and tribological behavior by employing universal testing machines, Vickers microhardness tester and ball-on-disc instruments. Tribological characteristics of the Al7075-based HMMNCs were observed via ball-on-disc tribometer apparatus with load (10, 15 and 20 N), time (15 min) and speed (300, 600 and 900 rpm). While investigating, it is perceived that that the wear, tensile strength, hardness and microstructure characteristics of the Al7075/Silicon carbide/Hexagonal-boron nitride and Al7075/Graphene/Hexagonal-boron nitride HMMNCs were superior over the Al7075 alloy. It is found that Vickers and Rockwell hardness of the Al7075/SiC/h-BN HMMNCs were superior by 36.87% and 16.29%, respectively, over the Al7075 specimen. Whereas, UTS of the Al7075/Graphene/h-BN HMMNCs were superior by 38.19% over the Al7075 alloy.
Unification of symmetries inside neural networks: transformer, feedforward and neural ODE
Authors: Hashimoto Koji , Hirono Yuji , Sannai Akiyoshi 
Published: June 2024

Abstract
Understanding the inner workings of neural networks, including transformers, remains one of the most challenging puzzles in machine learning. This study introduces a novel approach by applying the principles of gauge symmetries, a key concept in physics, to neural network architectures. By regarding model functions as physical observables, we find that parametric redundancies of various machine learning models can be interpreted as gauge symmetries. We mathematically formulate the parametric redundancies in neural ODEs, and find that their gauge symmetries are given by spacetime diffeomorphisms, which play a fundamental role in Einstein’s theory of gravity. Viewing neural ODEs as a continuum version of feedforward neural networks, we show that the parametric redundancies in feedforward neural networks are indeed lifted to diffeomorphisms in neural ODEs. We further extend our analysis to transformer models, finding natural correspondences with neural ODEs and their gauge symmetries. The concept of gauge symmetries sheds light on the complex behavior of deep learning models through physics and provides us with a unifying perspective for analyzing various machine learning architectures.
Biogenic synthesis of silver nanoparticle from flower extract of Wedelia chinensis and their antibacterial and antioxidant activity
Authors: Pandey Brajesh Chandra , Gupta Ashish , Sahu Alakh Niranjan , Dey Riddha , Raghuwanshi Richa , Kumari Nishi 
Published: June 2024

Abstract

Wedelia chinensis is a medicinal herb of the family Asteraceae. Green synthesis of silver nanoparticles (AgNPs) was done by using flower extract of Wedelia chinensis. Optimum conditions for AgNPs synthesis were as such: flower extract and AgNO3 (0.1 M) were taken in 1:9 ratio; temperature- 30 °C; reaction time- 12 h. UV-Visible spectra of the synthesized nanoparticle showed maximum absorption at 400 nm. Crystalline nature of silver nanoparticle was confirmed by XRD pattern. Through TEM, average size of AgNPs was observed as 51.2 nm. FTIR indicated participation of various functional groups of flower extract in the formation of nanoparticles. In DLS study, AgNPs of size 121 nm showed 100% intensity. Zeta potential was recorded as −1.24 mV. Strong peak of silver was observed in EDX study. AgNPs alone showed effective inhibition against all pathogenic bacteria taken as test organisms, but its combination with the antibiotics showed considerable enhancement in antibacterial activity. Inhibition for methicillin resistant Staphylococcus aureus (MRSA) was maximum when nanoparticles were taken in the combination of antibiotics and the extract. Significant antioxidant potential of AgNPs were observed in DPPH, ascorbic acid and DNA nicking assays. Thus, AgNPs of Wedelia chinensis flower extract showed significant medicinal efficacy as antioxidant and antibacterial.
Sufficiency of level 1 charging to meet electric vehicle charging requirements
Authors: Fried Aviv , Shaffer Blake , Hastings-Simon Sara 
Published: June 2024

Abstract
As electric vehicle (EV) deployment increases there is increasing attention to meeting charging needs. We analyze 13 months of real world driving and charging data for 129 battery electric vehicles in Calgary, Canada to evaluate the potential for home-based level 1 charging to deliver the energy needed to satisfy observed driving demand. We find that 29% of vehicles can have their energy needs met entirely with level 1 charging. A further 53% of vehicles in our sample require only occasional supplementary level 3 charges and only a small minority of vehicles require 12 or more supplementary level 3 charges across the sample period. Across all vehicles the median ratio of charge energy that can be shifted to level 1 charging is 0.99. These results challenge the assumption that level 2 charging access is required for convenient operation of EVs and offer a partial solution to enable broader EV charging access and reduce the need for near term electrical panel or distribution grid upgrades.
Micropolitics
Authors: Darby Derrick , Martinez Eduardo J 
Published: June 2024

Abstract
This chapter identifies three component civic responsibilities that must be taken up to ensure that identities facilitate accountable collective self-authorship (CSA) and how they apply to citizens acting in three different roles. It relies upon micropolitical case studies with a special focus on environmentalist examples. It calls special attention to the importance of coalition-building for advancing CSA projects and describes how civic responsibilities can be taken up in the context of coalitions. The chapter also includes a description of how taking up civic responsibilities can involve developing an ethos of CSA, as an alternative to an ethos of boxing in, and why these responsibilities are neither trivial nor overly demanding. It concludes with an analysis of the pitfall of political hobbyism and an account of the importance of taking up civic responsibilities as an organizer who contributes to the organizational infrastructure that CSA processes rely on.