bluuebunny/crossref_metadata_2025_split huggingface dataset:
A non-local way around the no-global-symmetries conjecture in quantum gravity?
Authors: Borissova Johanna , Eichhorn Astrid , Ray Shouryya 
Published: December 2024

Abstract
The no-global-symmetries conjecture is central to the swampland program that delineates the boundary between effective field theories that can be obtained from a quantum theory of gravity to those that cannot. The conjecture states that virtual black-hole configurations in the path integral generate terms that violate all global symmetries in the effective action for matter. Because of its central role, it is crucial to understand limitations to the validity of this conjecture. In the context of the Lorentzian path integral over spacetime geometries, we explore whether virtual black-hole configurations can be suppressed dynamically. To that end, we work in a spherically symmetric setting and make use of horizon-detecting curvature invariants which vanish on the horizon. By constructing a non-local gravitational action from the inverse of such curvature invariants, we can achieve destructive interference of black-hole configurations in the path integral. Given that non-local gravitational actions appear generically as the result of integrating out matter degrees of freedom from a theory for quantum gravity and matter, our exemplary construction reinforces discussions about the role of non-locality in assessing arguably universal properties of quantum gravity within the framework of path integrals.
A nested sequence of inequivalent Rindler vacua : universal relic thermality of Planckian origin
Authors: Lochan Kinjalk , Padmanabhan T 
Published: December 2024

Abstract
The Bogoliubov transformation connecting the standard inertial frame mode functions to the standard mode functions defined in the Rindler frame R
0, leads to the result that the inertial vacuum appears as a thermal state with temperature

T
0

=

a
0

/

2
π

where a
0 is the acceleration parameter of R
0. We construct an infinite family of nested Rindler-like coordinate systems

R
1

,

R
2

,

…

within the right Rindler wedge, with time coordinates

τ
1

,

τ
2

,

…

,

and acceleration parameters

a
1

,

a
2

,

…

by shifting the origin along the inertial x-axis by amounts

ℓ
1

,

ℓ
2

,
⋯

. We show that, apart from the inertial vacuum, the Rindler vacuum of the frame Rn
also appears to be a thermal state in the frame

R

n
+
1

with the temperature

a

n
+
1

/

2
π

. In fact, the Rindler frame

R

n
+
1

attributes to all the Rindler vacuum states of

R
1

,

R
2

,

…

R
n

, as well as to the inertial vacuum state, the same temperature

a

n
+
1

/

2
π

. We further show that our result is discontinuous in an essential way in the coordinate shift parameters. For a Rindler frame Ri
, this thermality turns on with smallest non-zero

ℓ
i

allowed in the semiclassical framework and remains insensitive to

(

ℓ
i

,

a

i
−
1

)

thereafter, indicating its universal Planckian origin. Similar structures can be introduced in the right wedge of any spacetime with bifurcate Killing horizon, like, for e.g. Schwarzschild spacetime. Apart from providing unsuppressed observables capturing Planck scale effects, these results have important implications for quantum gravity (QG) when flat spacetime is treated as the ground state of QG. Furthermore, a frame with the shift

ℓ

and the corresponding acceleration parameter

a
(
ℓ
)

can be thought of as a Rindler frame which is instantaneously comoving with the Einstein’s elevator moving with a variable acceleration. Our result suggests that the quantum temperature associated with such an Einstein’s elevator is the same as that defined in the comoving Rindler frame. The implications of these results are wide ranging, from having a definitive signature of Planck shifts in the horizon to the existence of a new set of observers in black hole exterior having thermodynamic description of the horizon they perceive.
Flat space gravity at finite cutoff
Authors: Banihashemi Batoul , Shaghoulian Edgar , Shashi Sanjit 
Published: December 2024

Abstract
We study the thermodynamics of Einstein gravity with vanishing cosmological constant subjected to conformal boundary conditions. Our focus is on comparing the series of subextensive terms to predictions from thermal effective field theory, with which we find agreement for the boundary theory on a spatial sphere, hyperbolic space, and flat space. We calculate the leading Wilson coefficients and observe that the first subextensive correction to the free energy is negative. This violates a conjectured bound on this coefficient in quantum field theory, which we interpret as a signal that gravity does not fully decouple in the putative boundary dual.
Resolving emission rates from overlapping capacitance transients of deep levels in SiC
Authors: Wang Zilan , Li Haoyang , Liu Bo , Yang Jiapeng , Lin Tianxiang , Ling Francis C C , Wang Lai 
Published: December 2024

Abstract
With the development of new materials and devices, defect characterization techniques, such as deep level transient spectroscopy, face the challenge of providing more accurate defect information and identification. However, nonexponential capacitance features are introduced for various reasons, making the widely adopted rate window technique encounter difficulties during analysis, which may lead to incorrect conclusions. In this study, the capacitance transients of a SiC junction barrier Schottky diode were systematically analyzed, revealing an overlap of majority and minority carrier trap emission signals within the same measurement temperature. Additionally, the capacitance transients of electron traps contained two similar emission rates. If the selection of rate window is inappropriate, it not only becomes difficult to distinguish each trap, but also false signals may appear. By comparing the rate window and exponential fitting method, the emission rates, activation energy, and capture cross-section can be calculated separately, and this comparative analysis may help improve reliability. Furthermore, the concentration profiles of each trap as a function of depth are analyzed by applying different voltages, and the possible origins of these traps are discussed.
Comprehensive scrutiny on the low temperature magnetism and hyperthermia efficiency of greenly synthesized biocompatible Zn0.25Ca0.25Fe2.5O4 nanoparticles
Authors: Tiwari Sudeep , Bano Anisha , Kamali Saeed , Williams Aleia , Johnson Jacqueline , Johnson Charles , Anandhi J Shebha , Patil Sagar Anandrao , Khot Vishwajeet M , Roychowdhury Parikshit , Eyal Anna , Kumar Sudhish 
Published: December 2024

Abstract
The present study comprehensively scrutinizes the complex magnetism and hyperthermia efficiency of greenly synthesized Zn0.25Ca0.25Fe2.5O4 nanoparticles (ZNCF NPs). ∼23 nm sized ZNCF NPs in single phase fcc-spinel symmetry were successfully produced through sugarcane juice-mediated self-combustion tactics. Biocompatibility examination against BEAS-2B cell lines indicated a safer limit of ZNCF NPs as 1 mg. Exhaustive field (upto ±70 kOe) and temperature-dependent (10 K to 300 K) dc-magnetization measurements showed that ZNCF NPs are in the ferrimagnetic (FiM) phase at low temperatures and superparamagnetic (SPM) along with minute magnetically hard FiM component at 300 K. 57Fe-Mössbauer analysis validated SPM (43%) and FiM (57%) at 293 K and FiM state at low temperatures. Observed isomer shift revealed that the majority of Fe ions are in a high spin Fe3+ state along with Fe2+ ions in ZNCF NPs. Shifting in the real part of ac—susceptibility data toward the higher temperature side upon increasing frequency and obeying Vogel–Fulcher law affirmed collective freezing of superspins below freezing temperature (T
f = 200 K). Dynamic scaling fit yielded relaxation time of ∼10−12 s, Mydosh parameter (=0.021) and critical exponent (8.9) ascertaining superspin glass (SSG) state in ZNCF NPs below glass temperature (T
g = 220 K). Furthermore, SSG phase at low temperatures is approved by archetypal experimental signatures like ageing, memory and rejuvenation. The induction heating characteristics of ZNCF NPs probed via infrared thermography yielded intrinsic loss parameter in the 0.26 nHm2 kg−1–5.10 nHm2 kg−1 range. Linear response theory provided non-zero power dissipation for ZNCF (suspension in de-ionized water) functioning range of 6–8 nm with an optimum particle size of ∼7 nm. A prudent analysis asserted that only 18% of NPs contribute to a non-zero SAR value. Overall, this research is an exhaustive investigation of the complex magnetism and hyperthermia efficiency suitable for mild hyperthermia applications.
High performance n-MoSe2/p-Ge-GeSn MQW/n-Ge heterojunction phototransistor for extended short-wave infrared photodetection
Authors: Wang Rui , Cai Xinwei , Yang Tianwei , Wu Qiang , Ding Haokun , Zhu Yiming , Lin Guangyang , Li Cheng 
Published: December 2024

Abstract
Germanium tin (GeSn) holds great potential for the development of monolithic short-wave infrared (SWIR) photodetectors. However, the large dark current and insufficient responsivity, resulting from the dense surface states and deteriorated crystal quality of high-Sn fraction GeSn thin films, pose significant challenges for their practical application. Herein, a fully strained GeSn-Ge multiple-quantum-well (MQW) bipolar heterojunction phototransistor (HPT) with an n-MoSe2/p-Ge van der Waals (vdW) heterostructure serving as the emitter-base junction is proposed to suppress dark current and enhance responsivity in the SWIR band. The fully strained GeSn-Ge MQWs are strategically employed as the absorption region, thereby extending the response wavelength up to 2000 nm and significantly reducing the dark current density. The developed HPT with a floating base achieves a low dark current density of 7.87 mA cm−2 at 2 V and a commendable responsivity of 1.3 A W−1 at 1550 nm along with rapid rise/fall times of 81.3 μs/73.1 μs. Furthermore, the phototransistor operates in self-powered mode, showcasing a high specific detectivity of 2.6 × 1010 Jones. These results suggest that the proposed GeSn-Ge MQW-based mix-dimensional vdW HPT can effectively suppress dark current and enhance detectivity for advanced SWIR imaging applications.
Swift heavy ion induced electronic structure modifications in ZnO thin films: X-ray absorption spectroscopy study
Authors: Gautam Sanjeev , Verma Monika , Thakur Anup , Chen Jin-Ming , Hwa Chae Keun 
Published: December 2024

Abstract
ZnO is a potential material for electronic device applications due to its versatile semiconducting properties with a direct band gap of 3.3 eV. This research represents a modification in the electronic structure of ZnO thin films (350 nm) irradiated with swift heavy ions (SHI) at different fluences. ZnO thin films were grown on a silicon substrate (100) using radio-frequency magnetron sputtering, which are highly oriented in a single phase/plane (002). The deposited thin films were subjected to SHI of 100 MeV O-ion with fluence of 3×1012 ions cm−2, 45 MeV Li-ion beams with fluence of 3×1012 ions cm−2 and 120 MeV Au-ion with varying fluence from 1×1011 to 5×1012 ions cm−2. SRIM/TRIM software was utilized to study theoretical effects of SHI like ion ranges, phonon energy, etc. Modifications in the structure and the electrical properties of ZnO thin films were investigated using high-resolution X-ray diffraction (HRXRD), Atomic Force Microscopy and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy at the O K- and Zn L

3
,
2

-edges. HRXRD employed for the structure, crystallinity, and phase of the system whereas NEXAFS for the local atom bonding symmetry via the molecular orbital hybridization between Zn and O. Furthermore, Density Functional Theory based on first principles FEFF9.6 has been incorporated for better understanding of NEXAFS while discussing the various parameters and cards. Simulations were performed to support the NEXAFS experimental data for the determination of various physical entities and their interpretations for diverse applications. NEXAFS measurements provide a deeper understanding of the effects of SHI for promising applications through the controlled fluence rate of ion beam irradiations.
C60 fullerene improves the contractile activity of the injured rat muscle gastrocnemius
Authors: Prylutskyy Yuriy , Nozdrenko Dmytro , Motuziuk Olexandr , Prylutska Svitlana , Nurishchenko Natalia , Franskevych Daria , Soroca Vasil , Cherepanov Vsevolod , Kalinin Ihor , Korzhyk Olha , Ritter Uwe 
Published: December 2024

Abstract
The powerful antioxidant properties of C60 fullerenes have been widely used in biomedical nanotechnology. Owing to the negative effects of free radicals in oxidative stress processes, antioxidants are required to protect injured muscles. Here, the effect of water-soluble C60 fullerenes (daily oral dose 1 mg kg−1) on the process of restoration of contractile activity of skeletal muscle of rats (muscle gastrocnemius) 15 d after the initiation of open trauma of different severity was studied for the first time. The structural organization of C60 fullerene nanoparticles in aqueous solution was analyzed by dynamic light scattering and atomic force microscopy techniques. Such biomechanical parameters of muscle gastrocnemius contraction as integrated muscle power, levels of generation of its maximum and minimum force, and time interval until reaching 50% of the level of force response of the muscle were analyzed. Such biochemical indices as concentrations of c-reactive protein, creatinine, and lactate in the rat blood, as well as indices of pro- and antioxidant balance (activities of superoxide dismutase and catalase, the concentration of reduced glutathione) in the blood and muscle tissue of experimental animals, were investigated. It was found that application of water-soluble C60 fullerenes statistically significantly improves biomechanical parameters of contraction of injured muscle gastrocnemius at the level of 30–45 ± 3%, which is confirmed by normalization of biochemical indices in the blood and muscle tissue of rats at the level of 35–50 ± 3% and 20–37 ± 3%, correspondingly, relative to the open injury group. These findings open the possibility of using C60 fullerenes as potential therapeutic nanoagents capable of correcting pathological states of the muscular system during the physiological repair of open injuries.
Preparation of novel B/ZnO/zeolite nanocomposites by simple combustion method for enhanced dye removal in an aqueous environment
Authors: Nguyen Thu Huong , Van Duong Le , Vu Anh-Tuan 
Published: December 2024

Abstract
In this study, the mixture of zinc acetate dehydrates and boric acid was pyrolyzed in zeolite X to prepare novel B/ZnO/zeolite nanocomposites for the enhanced removal of tartrazine (TA) in aqueous environment. The composites are porous material with a relatively large pore size (35.3 nm). The surface area of the composite (19.72 m2 g−1) is smaller than that of zeolite (248.78 m2 g−1), but its adsorption capacity is quite high (q
max of 97.6 mg g−1). The factors influencing the adsorption process were investigated in detail. Under the optimal conditions (the initial dye concentration of 20 mg l−1, the adsorbent content of 0.5 g l−1, pH equal 6, and the temperature of 25

°

C

), the removal efficiency (R
e) was 97.5%. The first and second-order equations were used to model the kinetic adsorption. The Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models were used to study isothermal adsorption. In addition, the thermodynamic of adsorption was also investigated. The ΔH
o of −52.423

±

2.306 kJ mol−1 indicates the exothermic process and the negative ΔG
o indicates a spontaneous process. At low temperatures, the adsorption of TA proceeds smoother and more effectively, and the negative ΔS
o (−129.638 7.376 J·mol−1·K−1) indicates a decrease in the degree of freedom of the adsorbed species. The adsorption mechanism was also proposed.
A simple and versatile dual-state variable stiffness structure based on microwedge dry adhesives
Authors: Chen Gen , Bao Tingting , Chu Zhongyi , Cui Jing 
Published: December 2024

Abstract
The integration of softness and rigidity underpins the concept of variable stiffness, leveraging the distinct advantages of both properties. Inspired by this concept, this paper introduces a stiffness-switchable composite structure achieved through laminar jamming enabled by the inherent dry adhesion force of microwedge adhesives. This mechanism allows for a reversible transition between high flexibility and pronounced rigidity, achieving a remarkable stiffness ratio of 75, with easier implementation and enhanced functionality. Comprehensive modeling and experimentation are conducted to reveal intricate aspects of the structure’s mechanical properties, such as interlayer behavior and failure processes. This paper also outlines two potential applications for this multifunctional structure: a robotic gripper with dual modes of rigid pinch and compliant adhesion, and an integrated multifunctional sensing setup. The proposed structure might broaden the scope of dry adhesives and laminar jamming structures, suggesting new possibilities for future research and development.
Advanced processing techniques for electric field-guided electrospinning of self-organized Ag nanoparticle electrodes for real-time humidity and temperature sensing
Authors: Aoboun Assareeya , Pechyen Chiravoot , Shin Dong-Youn 
Published: December 2024

Abstract
With the rapid expansion of flexible electronics, there is an urgent need for sustainable production methods that enhance device performance while minimizing environmental impact. This work presents an innovative, green approach for fabricating flexible, patterned electrodes via electric field-driven self-organization of conductive fibers onto flexible substrates. By applying high voltage to both the dispensing nozzle and an underlying printed circuit board substrate, the system leverages controlled electric fields to direct fiber jets with precision, eliminating the need for conventional masking techniques. The fiber composition-polyethylene oxide integrated with silver nanoparticles-provides both conductivity and environmental compatibility. This streamlined technique notably reduces material usage, processing time, and chemical waste. Practical demonstrations involve the construction of flexible conductive electrodes for humidity and temperature sensors, achieving a low sheet resistance near 10 Ω sq−1, attesting to the method’s functional viability. The process ensures precise fiber alignment and consistent deposition, paving the way for its integration into flexible sensor and device applications. This study underscores the potential of electric field manipulation to revolutionize coating processes for sustainable and scalable production in flexible electronics.
Modeling of shear wave propagation in piezo-viscoelastic microbeam over quadratic heterogeneous viscoelastic plate with sliding contact
Authors: Sadab Mohd , Kundu Santimoy 
Published: December 2024

Abstract
This study analyzes the phase and attenuation dynamic behavior of piezo-viscoelastic microbeam overlying quadratic heterogeneous viscoelastic plate under sliding contact. Using the Kelvin–Voigt model, the material properties of the system are assumed to be viscoelastic. Maxwell’s relations are used to incorporate the electric potential function. The solutions for both media are derived separately by solving the second-order hyperbolic differential equation using the method of separation of variables and expansions of Bessel functions. The system of linear homogeneous equations is obtained by applying admissible boundary conditions to determine fundamental physical quantities. The key contribution of the current work is demonstrating the influence of dissipation factors, sliding contact, micro-length, heterogeneity, and thickness ratio parameters on shear wave propagation. The micro-length effect is found to suppress the attenuation of shear waves through the analysis and discussion of the dispersion and attenuation curves.
Radiation protection: assessing the shielding performance of iron-reinforced polydimethylsiloxane in comparison to lead
Authors: Yazdankish Enayatolah , Nejatolahi Mostafa , Ghobadpouri Saeed 
Published: December 2024

Abstract
This study evaluates the radiation shielding properties of Polydimethylsiloxane reinforced with iron. Using the Py-MLBUF program, we calculated and compared the mass attenuation coefficient, linear attenuation coefficient, half-value layer, effective atomic number, and effective electron number with those of lead. The dominance of the photoelectric effect at lower energies and pair production at higher energies is observed. The contribution of Compton scattering remains relatively constant across the energy spectrum, while Rayleigh scattering is negligible. At lower energy levels, composites reinforced with higher iron weight fractions demonstrate higher mass attenuation and linear attenuation coefficients. Increasing iron weight fractions reduces the half-value layer, improving radiation attenuation up to a threshold. The results show that while lead generally has higher attenuation coefficients, the difference is negligible at energies between 0.7 and 4 MeV. Although lead has lower half-value and tenth-value layers, higher iron weight fractions in PDMS also, provide good radiation shielding due to increased effective atomic and electron numbers. Fe-reinforced PDMS at weight fractions of 10%, 20%, 40%, and 60% show significant potential for radiation shielding, especially in the 0.7 to 4 MeV photon energy range, and in applications requiring flexibility and lightweight materials.
Synthesis and characterization of corn cob activated carbon for Pb(II) adsorption with real-time monitoring using internet of things
Authors: Muh Amar Masyhudul Haq , Tahir Dahlang , Heryanto Heryanto , Abdelilah Akouibaa , Alomari Ali , Setiawan Vicram , Putri Suriati Eka 
Published: December 2024

Abstract
Here, we investigate the adsorption of Pb(II) using AC derived from corn Rachis (RAC) with various carbonization temperatures: 500 °C, 700 °C, and 900 °C using KOH solution as the activator. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the presence of hydroxyl and carbonyl functional groups and optical-dielectric function change under the carbonization process. X-ray Diffraction (XRD) patterns confirmed the presence of (002) and (100) lattice planes, indicating a graphitic phase with amorphous area (

X

a

) domination. Scanning Electron Microscopy (SEM) images showed a honeycomb-like morphology, while Energy Dispersive x-ray (EDX) analysis indicated a carbon content of over 90%. Brunauer–Emmett–Teller (BET) analysis shows the high specific surface area of each sample (>1000 m2/g). The highest Pb(II) adsorption efficiency was achieved at 99.77%, with maximum performance at pH = 7.31, and temperature ∼26.7 °C, supported by the narrowing phonon vibration (

Δ

LO
−
TO

, lower electron loss function (ELF) shifts in wavenumber, higher

X

a

, and confirmed through adsorption kinetic and isotherm study. Here, we demonstrate a fresh methodology based on real-time monitoring using the Internet of Things of RAC as a promising adsorbent for Pb(II) removal with an adsorption capacity of 2.598 mg g−1. In addition, the ability of adsorption results without stirring aids to determine their ability when applied to the environment has been studied.