bluuebunny/crossref_metadata_2025_split huggingface dataset:
Entropy production due to spacetime fluctuations
Authors: Moreira Thiago H , Céleri Lucas C 
Published: December 2024

Abstract
Understanding the quantum nature of the gravitational field is undoubtedly one of the greatest challenges in theoretical physics. Despite significant progress, a complete and consistent theory remains elusive. However, in the weak field approximation—where curvature effects are small—we can explore some expected properties of such a theory. Particularly relevant to this study is the quantum nature of gravitational waves, which are represented as small perturbations in flat spacetime. In this framework, a quantum description of these perturbations, as a quantum field, is feasible, leading to the emergence of the graviton. Here we consider a non-relativistic quantum system interacting with such a field. We employ the consistent histories approach to quantum mechanics, which allows us to frame classical questions in a quantum context, to define a fluctuation relation for this system. As a result, thermodynamic entropy must be produced in the system due to its unavoidable interaction with the quantum fluctuations of spacetime.
Loop group factorization method for the magnetic and thermostatic nonabelian ray transforms
Authors: Jathar Shubham R , Kar Manas , Railo Jesse 
Published: December 2024

Abstract
We study the injectivity of the matrix attenuated and nonabelian ray transforms on compact surfaces with boundary for nontrapping λ-geodesic flows and the general linear group of invertible complex matrices. We generalize the loop group factorization argument of Paternain and Salo to reduce to the setting of the unitary group when λ has the vertical Fourier degree at most 2. This covers the magnetic and thermostatic flows as special cases. Our article settles the general injectivity question of the nonabelian ray transform for simple magnetic flows in combination with an earlier result by Ainsworth. We stress that the injectivity question in the unitary case for simple Gaussian thermostats remains open. Furthermore, we observe that the loop group argument does not apply when λ has higher Fourier modes.
A method for classification of chest motion base on time-domain signals of IR-UWB radar
Authors: Huang Zhitong , Ma Yongtao , Han Yuxiang 
Published: December 2024

Abstract
As an instrument for wireless sensing and measurement, radar is widely used in target tracking and localization. And Impulse Radio Ultra-Wideband (IR-UWB) radar, with its excellent characteristics of high resolution and large bandwidth, has become a research hotspot in the fields of perception and ranging, smart home and so on. However, when radar sampling rates are low, it is often difficult to obtain accurate time domain information. Also when the amplitude of human movement is too tiny, It’s hard to recognize human activity only based on radar images. This paper proposes a novel method to classify small amplitude human chest motions by time-domain signal from IR-UWB radar with a low sampling rate. Based on the energy and phase of the radar echoes, our method can detect the onset of human’s motion and differentiate between normal breathing and apnea. Additionally, the amplitude of human’s motion can be distinguished based on the distance range spanned by the echoes. Finally, a two-step classification method is employed to distinguish between yawning and coughing in small motions. The paper reports a classification precision of 0.9186, recall rate of 0.9163, and F1 score of 0.9172 for the proposed method under experimental conditions. The experimental performance outperformed the adopted comparison method based on ResNet50, MobileNetV3 and MobileViT. We also tested the performance of the proposed method under different angle and distance conditions, which demonstrates the feasibility of our method.
Denoising proton reference dosimetry spectrum using a large area ionization chamber—physical basis and type A uncertainty
Authors: Tan Hong Qi , Lew Kah Seng , Koh Calvin Wei Yang , Lee Kang Hao , Chua Clifford Ghee Ann , Wibawa Andrew , Master Zubin , Lee James Cheow Lei , Park Sung Yong 
Published: December 2024

Abstract

Objective. Reference dosimetry measurement in a pencil beam scanning system can exhibit dose fluctuation due to intra-spill spot positional drift. This results in a noisy reference dosimetry measurement against energy which could introduce errors in monitor unit calibration. The aim of this study is to investigate the impact of smoothing the reference dosimetry measurements on the type A uncertainty. Methods. The reference dosimetry measurement (

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with a PTW 34045 advanced Markus chamber placed at 2 cm depth and a 10 × 10

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m

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scanned field are performed for 98 energy layers on five non-consecutive days using a water tank. The PTW 34089 large area ionization chamber (LAIC) is placed at the same depth and the charges are measured with a single spot irradiation (

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spot

LAIC

). (

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and

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spot

LAIC

are fitted with a linear and quadratic function to obtain a smooth plot of (

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against the proton energy (reference dosimetry curve). Type A uncertainty of the measured reference dosimetry curve is compared against the de-noised fitted curve. Results. The repeatability of reference dosimetry measurement shows relative difference of up to 2.3% across the five days. The linear and quadratic fits between LAIC charges and the (

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from PTW 34045 show a high

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values of more than 0.95. The maximum type A uncertainty of the de-noised reference dosimetry curve is lower (0.69% at 70.2 MeV) compared to the measured one (0.88% at 77.5 MeV). However, the average type A uncertainty of the denoised curve across all energies is higher compared to the measurements (0.50% versus 0.43%). Conclusion. We have presented the physical basis and procedure for fitting the charges measured with a LAIC to the reference dosimetry curve. The fitted reference dosimetry curve avoids large error in any energy layer but increases the average type A uncertainty across energies and should be used with caution.
A piezoelectric coded-excitation scanning acoustic transducer for Lamb wave inspections
Authors: Dibiase Marco , Mohammadgholiha Masoud , De Marchi Luca 
Published: December 2024

Abstract
Several techniques for Guided Wave (GW) inspections have already been developed. Most of them rely on extensive sensor deployment and damage localization algorithms characterized by significant computational costs. However, there is a growing demand for simpler, more autonomous, and more affordable systems across various fields. In particular, the implementation of wireless, battery-powered systems with a reduced number of sensor nodes and simpler processing would greatly facilitate the transition of this inspection technology on the field. Following this direction, this work presents the design of a novel piezoelectric transducer composed of four different patches, i.e. with only four input/output channels, to scan a given area. The peculiar piezo-load distributions allow the association of different spectral binary sequences for each 6∘ discrete angular step. By evaluating the distance-of-flights (DoFs) of detected peaks, the range coordinates for multiple defects are identified. Meanwhile, the angular information is extracted by demodulating binary sequences of peaks with comparable DoFs across several frequency bands. Since the transducer is designed as an encoder, it is referred to as coded-excitation scanning acoustic transducer (CESAT). More specifically, the Gray code is used to generate spectral patterns to reduce the uncertainty between two adjacent angular steps. A new quantization procedure for the optimal generation of the piezo distributions is also proposed. Ad hoc signal processing algorithms, suitable for embedded applications, were developed to extract multi-target range and angle information. The processing is based on the frequency decomposition of the recorded signal using an FIR filter bank and on dispersion compensation procedures for pulse ‘re-compression’. The transducer encoder behavior is validated through a finite element analysis. Finally, numerical simulations were performed to assess the effectiveness of the CESAT and associated signal processing in multi-defect detection and localization tasks.
Adaptive stiffness structures via additively manufactured fluid accumulators
Authors: Saxena Ankit , Manogharan Guha , Rahn Christopher 
Published: December 2024

Abstract
Lightweight mechanical structures often have low stiffness that prevents their use in structural applications. The demand for lightweight mechanical structures that operate under wide-ranging loading conditions motivates the development of adaptive stiffness structures. The ability to control the stiffness of a mechanical structure allows for tailored static and dynamic properties, including resonant frequencies. However, adaptive stiffness structures that are low cost, offer design flexibility, and can be additively manufactured still remain a challenge. To this end, we introduce adaptive stiffness devices called pressure-actuated adaptive structural cells (PASCells) with controllable axial stiffness. The proposed PASCells consist of four, flat arches that seal at the edges to contain a working fluid. The axial stiffness of the PASCell increases when the enclosed working fluid is compressed due to volume reduction under an axial load. Axial compression of a PASCell creates large internal volume change and internal pressure that resists this compression, increasing stiffness when the fluid volume is constrained by, for example, closing an outlet valve. Designed for additive manufacturing, PASCells can be integrated with mechanical structures to enable adaptive stiffness. In this paper, we derive the governing equations that describe the static deformation of PASCells under an axial load and internal pressurization and experimentally evaluate the stiffness of the PASCells in empty (or open valve) and filled (or closed valve) configurations. Single, series-connected, and parallel-connected PASCells are additively manufactured and experimentally tested, verifying the model predictions, and experimentally demonstrating a 70% stiffness increase.
Dynamically switchable multifunctional device for terahertz application using vanadium dioxide and graphene-based metasurface
Authors: Mistri Hiranmay , Ghosh Anumoy , Sardar Abdur Rahaman , Roy Pabitra 
Published: December 2024

Abstract
In this article, a dynamically switchable and multifunctional metasurface is realized using a combination of vanadium dioxide (VO2) and graphene-based structures. The device can be tuned using the temperature transition property of vanadium dioxide from a wideband linear-to-circular polarization converter (LTCPC) to a wideband linear-to-linear cross polarization converter (LTLPC) and a dual-band absorber. The unit cell is designed with a gold-backed lossy-silicon dioxide (SiO2) substrate with a permittivity of 3.9, and the top metasurface layer is designed with a graphene-based dual triangle loaded split ring (DTLSR) and two stripes of vanadium oxide to cover the split partially. The proposed device can be used as a wideband LTCPC at normal temperature (298 K) from 1.43 THz to 2.85 THz, i.e., 66.35% fractional bandwidth (FBW). At temperatures greater than 341 K, VO2 exhibits metallic properties, and the structure functions as LTLPC from 1.82 THz to 3.31 THz (PCR ≥ 80%), i.e., 58.08% FBW and maximum polarization conversion ratio (PCR) reported as high as 99.65%. Furthermore, at this metallic condition, two absorption peaks are obtained at 1.22 THz and 3.30 THz with absorptivity of 93.5% and 100%, respectively. The device offers incident angle invariability up to 40° for LTCPC and up to 50° for LTLPC operation. Further insight into the mechanism of operation is developed using the surface current density and electric field distribution analysis. The advantage of the proposed metasurface over other similar structures is assessed with respect to multifunctional behavior, bandwidth, and stability under oblique incidence.
Extra-cavity modulating a dark bisoliton
Authors: Wang Dayu , Zhang Yusong , Wang Haoming , Tang Daqian , Zhan Junxiao , Zhou Yan 
Published: December 2024

Abstract
Although the concept of modulating optical solitons out of fiber laser cavities has already been proposed, to more flexibly change optical solitons’ time or frequency domain properties, compared with traditional intra-cavity modulation. The extra-cavity modulation of dark bisolitons has seldom been touched upon. In this manuscript, we theoretically conduct the research about modulating a dark bisoliton at 1 μm wavelength regime, in an extra-cavity modulation system. The modulation system is composed of different modulation elements. In the simulation, we consider the variations of different parameters. And modulated dark bisoliton’s orthogonal polarization components will show unique variation properties as these soliton parameters vary. For example, as time delay in orthogonal directions varies, a new small pulse peak appears at the position of continuous wave background in vertical polarization direction at output port, when time delay reaches to a specific value. These simulation results further explore the extra-cavity modulation of dark pulses in nonlinear optical fiber modulation systems, which are useful to understand the dark bisolitons’ dynamics in extra-cavity modulation systems. And these results have potential applications in the field of high-speed and long-distance optical fiber communication.
Disentangling electronic and phononic thermal transport across two-dimensional interfaces
Authors: Zhai 翟 Linxin 麟鑫 , Xu 徐 Zhiping 志平 
Published: December 2024

Abstract
Electrical and thermal transport at two-dimensional (2D) interfaces is critical for semiconductor technology, yet their interplay remains unclear. We report a theoretical proposal to separate electronic and phononic contributions to thermal conductance at 2D interfaces with graphene, which is validated by non-equilibrium Green’s function calculations and molecular dynamics simulations for graphene–gold contacts. Our results reveal that while metal–graphene interfaces are transparent for both electrons and phonons, non-covalent graphene interfaces block electronic tunneling beyond two layers but not phonon transport. This suggests that the Wiedemann–Franz law can be experimentally tested by measuring transport across interfaces with varying graphene layers.
Enhanced Indonesian Throughflow heat transport prolongs the recharge process during triple La Niña events
Authors: Cao Ziyang , Li Mingting , Gordon Arnold L , Wang Dongxiao 
Published: December 2024

Abstract
The Indonesian Throughflow (ITF) serves as the only tropical branch of the Great Ocean Conveyer Belt, and plays an important role in Indo-Pacific Basin interactions. By calculating the heat budget during single and triple La Niña events (1973–1976, 1998–2000, 2020–2023), we quantified the contribution of enhanced ITF heat transport to prolonging the recharge process during triple La Niña events. During triple La Niña events, the accumulated heat transported by the ITF is about −15.01 ZJ (more than twice that for single events), nearly offsetting the positive contribution of net heat flux from the atmosphere over the Pacific Ocean. Single La Niña events are confined to thermal processes within the Pacific Ocean, while triple events are products of basin interactions, and the ITF serves as a crucial oceanic link between the tropical Indian and Pacific Oceans. The enhanced heat transport of the ITF is concentrated in the subsurface layer (100–200 m), significantly during the second year of a triple La Niña event. The accumulation of enhanced ITF heat transport in the subsurface layer effectively expands the recharge–discharge area from the western Pacific to the eastern Indian Ocean, with the ensuing discharge process of the tropical Indian Ocean along with sustained La Niña conditions in the Pacific Ocean.
Evaluation of artificial intelligence and optical image recognition techniques used in OneIso, an off-axis Winston-Lutz quality assurance phantom
Authors: Grafil Elliot M , De Jean Paul , Capaldi Dante P I , Skinner Lawrie B , Xing Lei , Yu Amy S 
Published: December 2024

Abstract
Single-isocenter multitarget (SIMT) stereotactic-radiosurgery (SRS) has recently emerged as a powerful treatment regimen for intracranial tumors. With high specificity, SIMT SRS allows for rapid, high-dose delivery while maintaining integrity of adjacent healthy tissues and minimizing neurocognitive damage to patients. Highly robust and accurate quality assurance (QA) tests are critical to minimize off-targets and damage to surrounding healthy tissues. We have developed a novel QA phantom, named OneIso, to accurately and precisely measure off-axis accuracy, via off-axis Winston-Lutz (OAWL), to assist SIMT SRS programs. In this study, a comparison of three different quantitative numerical methods were performed for isolating and measuring the position of ball-bearings (BBs) used in the OAWL measurement. The three methods evaluated were: 1) feature extraction technique combined with manual intervention 2) a proprietary software utilizing optical image recognition (OIR) techniques, and 3) a machine learning (ML) model employing convolutional neural networks (CNNs). These methods were used to analyze OAWL datasets gathered from a OneIso phantom deployed on a Varian TrueBeam. The precision of localizing positional BBs within the OneIso QA phantom, analysis speed, and robustness were compared across the methods. Significantly, the trained ML model utilizing CNNs was found to exhibit superior precision, analysis speed, and efficiency compared to the other two methods. These results highlight the benefit in shifting from manual and OIR methods to that of ML techniques. The incorporation of CNNs in automated QA analysis can achieve improved precision, allowing for more rapid and wider adoption of SIMT SRS for treating intracranial metastases while preserving integrity of surrounding healthy tissues.
Enhancing performance of antimony selenide solar cell with different back surface field configurations
Authors: Chaudhary Pooja , Chauhan R K , Mishra Rajan 
Published: December 2024

Abstract
This study focuses on optimization of solar cells using antimony selenide (Sb2Se3) as absorber layer. A novel solar cell structure, designed and simulated with configuration ZnO/i-ZnO/Sb2Se3/NiO or SnS, demonstrates a notable efficiency improvement. The performance of this solar cell was rigorously evaluated using the SCAPS simulation tool. Key structural parameters were optimized as follows: ZnO at 30 nm, i-ZnO at 20 nm, Sb2Se3 as active layer at 100 nm, and NiO at 20 nm. NiO & SnS, utilized as a back surface field (BSF), effectively minimizes recombination. Various parameters were analyzed, including the band diagram, thickness, bandgap, doping concentration, effect of concentration on electric field, recombination and generation rates, temperature effects, and series and shunt resistance of proposed structure. The proposed model achieved an efficiency of up to 31.4%, highlighting the potential of NiO & SnS as BSF in antimony selenide solar cells. The metal work functions for front and back contacts are 4.4 eV and 5.1 eV respectively. This breakthrough suggests a transformative path toward significantly enhanced solar cell performance, showcasing the latent potential of NiO BSF in optimizing Sb2Se3-based solar cells.
How I diagnose high-grade B-cell lymphoma
Authors: Moore Erika M , Gibson Sarah E 
Published: December 2024

Abstract

Objectives
High-grade B-cell lymphoma (HGBL), introduced in the 2016 World Health Organization (WHO) revised fourth edition classification, included cases defined by MYC and BCL2 and/or BCL6 rearrangements or by high-grade morphology. Diagnostic criteria and nomenclature for these lymphomas were refined in the 2022 WHO fifth edition (WHO-5) classification and International Consensus Classification (ICC). This review describes our approach to the diagnosis of HGBL.

Methods
Two cases are presented illustrating how we diagnose HGBL, including 1 case harboring MYC and BCL6 rearrangements and a second showing TdT expression in an HGBL with MYC and BCL2 rearrangements. The ways in which these cases are distinguished from other lymphomas with high-grade features and the appropriate nomenclature using WHO-5 and ICC classifications are emphasized.

Results
An HGBL diagnosis requires integration of morphology, immunophenotype, and genetics and exclusion of other lymphomas with high-grade morphology, including Burkitt lymphoma, B-lymphoblastic leukemia/lymphoma (B-LBL/ALL), and blastoid mantle cell lymphoma. A diagnosis of HGBL/large B-cell lymphoma with 11q aberration should also be considered in certain patient populations.

Conclusions
High-grade B-cell lymphomas are subclassified based on morphologic and genetic features. There are differences in the nomenclature and definition of these lymphomas in the WHO-5 and ICC classifications. Distinguishing HGBLs from other mature B-cell lymphomas and B-LBL/ALL is critical so that patients receive appropriate treatment.
Evolutionary diversification of C2 photosynthesis in the grass genus Homolepis (Arthropogoninae)
Authors: Alvarenga Joyce Pereira , Stata Matt , Sage Rowan F , Patel Ria , das Chagas Mendonca Ane Marcela , Della Torre Felipe , Liu Hongbing , Cheng Shifeng , Weake Samantha , Watanabe Emile J , Lage Viana Pedro , de Castro Arruda Iago Augusto , Ludwig Martha , Delfino Barbosa João Paulo Rodrigues Alves , Sage Tammy L 
Published: December 2024

Abstract

Background and Aims
To better understand C4 evolution in monocots, we characterized C3–C4 intermediate phenotypes in the grass genus Homolepis (subtribe Arthropogoninae).

Methods
Carbon isotope ratio (δ13C), leaf gas exchange, mesophyll (M) and bundle sheath (BS) tissue characteristics, organelle size and numbers in M and BS tissue, and tissue distribution of the P-subunit of glycine decarboxylase (GLDP) were determined for five Homolepis species and the C4 grass Mesosetum loliiforme from a phylogenetic sister clade. We generated a transcriptome-based phylogeny for Homolepis and Mesosetum species to interpret physiological and anatomical patterns in an evolutionary context, and to test for hybridization.

Key Results
Homolepis contains two C3 species (H. glutinosa, H. villaricensis), one species with a weaker form of C2 termed sub-C2 (H. isocalycia), and two C2 species (H. longispicula, H. aturensis). Homolepis longispicula and H. aturensis express over 85 % of leaf glycine in centripetal mitochondria within the BS, and have increased fractions of leaf chloroplasts, mitochondria and peroxisomes within the BS relative to H. glutinosa. Analysis of leaf gas exchange, cell ultrastructure and transcript expression show M. loliiforme is a C4 plant of the NADP-malic enzyme subtype. Homolepis comprises two sister clades, one containing H. glutinosa and H. villaricensis and the second H. longispicula and H. aturensis. Homolepis isocalycia is of hybrid origin, its parents being H. aturensis and a common ancestor of the C3 Homolepis clade and H. longispicula.

Conclusions
Photosynthetic activation of BS tissue in the sub-C2 and C2 species of Homolepis is similar to patterns observed in C3–C4 intermediate eudicots, indicating common evolutionary pathways from C3 to C4 photosynthesis in these disparate clades. Hybridization can diversify the C3–C4 intermediate character state and should be considered in reconstructing putative ancestral states using phylogenetic analyses.