bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of fiber dispersion on fiber breakage in simple shear flow of long fiber-reinforced thermoplastics
Authors: Hohoff Paula , Perez Hector Sebastian , Wiegand Jan-Joris , Yanev Angel , Osswald Tim
Published: December 2024

The overall strength of parts made from fiber-reinforced composites is directly related to the fiber length. For long fiber-reinforced thermoplastics (LFTs), longer fibers lead to better mechanical properties. During the processing of the LFT raw material, fibers provided in LFT pellets with fiber bundles coated by a thermoplastic matrix break due to high stresses, which can lead to a reduction in fiber length from the initial 10–15 mm down to 1–3 mm in the final part. To accurately predict the performance of the final part, modeling the breakage of the fibers during processing is of high importance. Even though most fiber breakage is thought to occur during the breakup of fiber bundles, the impact of dispersion of the fibers on their breakage behavior is not well understood, and modeling approaches are lacking. This study investigates the impact of fiber dispersion on fiber breakage in simple shear flow to provide groundwork for accurately modeling the breakage of fibers during plastication of LFTs. LFT material is pre-dispersed to varying extents before being sheared in a simple Couette flow with different shear rates. The resulting fiber length is measured at different times to analyze the breakage behavior of fibers depending on shear rate and pre-dispersion.
Engineering perpendicular magnetic anisotropy and Dzyaloshinskii–Moriya interaction in Gd–Fe thin films for spintronics applications
Authors: Kumar Mishra Saroj , Prasanth Perumal Hari , Mohanty J.
Published: December 2024

Understanding symmetry breaking has led to various intriguing physical mechanisms and their implications for developing technologically important devices. In magnetic materials, broken inversion symmetry with strong spin–orbit coupling gives rise to Dzyaloshinkii–Moriya interaction (DMI), which favors the formation of topological spin textures and is envisioned as information carriers in spintronic devices. In this study, we prepared Gd–Fe thin films of various thicknesses grown by E-beam deposition. We observed the formation of elongated periodic stripe domains with strong magnetic phase contrasts after demagnetization, signifying the development of perpendicular magnetic anisotropy (PMA). Using a well-known analytical domain spacing model, we extracted the DMI value from the stripe domain periodicity combined with magnetometry data. Micromagnetic simulations corroborated the formation of stripe domains based on the analytically estimated DMI values. It is understood that broken inversion symmetry exists between the sublattices of Gd and Fe atoms due to the asymmetric distribution of the elemental content, which gives rise to such a phenomenon. Furthermore, the presence of such PMA and DMI without a heavy metal layer can be an exciting platform for spintronics-based magnetic memory devices.
A topographic mapping for dimensionality reduction in inverse design problems
Authors: Zhao Ying , Song Chao , Zhou Zhu , Chen Yan , Wang Yutong , Cai Jinsheng
Published: December 2024

The inverse design methods for aerodynamic shapes face significant challenges, especially in specifying reasonable distributions of target pressure and achieving the comprehensive optimization of aerodynamic characteristics. To overcome the limitations of existing inverse design methods, a nonlinear dimensionality reduction method based on topographic mapping was proposed. In this work, a high-precision bidirectional mapping between aerodynamic shape and its pressure distributions and low-dimensional latent space variables was built using the generative topographic mapping (GTM) model. This method, combined with the genetic algorithm, could provide efficient optimization in the latent space without the computational fluid dynamics iteration, yielding the optimal pressure distribution and the corresponding aerodynamic shape. It did not require the target pressure distribution to have direct physical significant, but instead uses coefficients to integrate the target pressure distribution and different aerodynamic performances into a hybrid objective function, achieving comprehensive aerodynamic optimization. In addition, this method was applied to high-speed natural laminar flow (HSNLF)(1)–0213 airfoil. The results revealed that a local pressure distribution of the optimal airfoil was close to the target distribution, and the total drag was reduced by 15.3%. Moreover, this method was applied to the complex multi-objective optimization design of the XN12 rotor airfoil, considering various performance metrics such as the maximum lift coefficient, cruise drag reduction, and drag divergence Mach number. The results demonstrated that the drag divergence Mach number of the optimized airfoil was significantly improved, achieving a balance between various performance metrics.
Computational analysis of the effect of interaction heterogeneity on fluid–crystal coexistence in micron-scale colloidal systems
Authors: Wu Po-Ting , Crocker John C. , Sinno Talid
Published: December 2024

Micron-scale colloidal particles with short-ranged attractions, e.g., colloids functionalized with single-stranded DNA oligomers, have emerged as a powerful platform for studying colloidal self-assembly phenomena with the long-term goal of identifying routes for metamaterial fabrication. Although these systems have been investigated extensively both experimentally and computationally, the role of “real world” features that may impact self-assembly in unexpected ways has been largely ignored. One such example of an important, yet underappreciated, feature is interaction heterogeneity (IH), i.e., variations in interparticle interaction strengths, which can arise from variability in the DNA strand areal density on particle surfaces during fabrication. A previous study demonstrated that IH can modulate nucleation and gelation kinetics under non-equilibrium conditions. Here, we investigate in detail the dependence of bulk fluid–crystal coexistence on IH. Using a multicomponent coexistence tracing approach, we compute phase diagrams for both Gaussian and bidisperse IH distributions, revealing that IH shifts the fluid-side coexistence boundaries outward, promoting crystallization at lower particle volume fractions while also resulting in crystals that are enhanced in the stronger binding species. Our results demonstrate that IH significantly influences crystallization behavior even under equilibrium conditions and provide a new perspective on tuning IH as a controllable parameter for optimizing colloidal self-assembly.
Tunneling and conformational preferences in racemic- and meso-2,4-pentanediol: A rotational spectroscopic and theoretical investigation
Authors: Carlson Colton D. , D’Souza Mason , Ma Jiarui , Mort Alex N. , Insausti Aran , Xu Yunjie
Published: December 2024

The rotational spectra of a mixture of 2,4-pentanediol (PDL) isomers, comprising both the meso isomers [(2R, 4S) and (2S, 4R)] and the racemic isomers [(2R, 4R) and (2S, 4S)], were recorded using a chirped-pulse Fourier transform microwave spectrometer coupled to a supersonic jet expansion. The conformational landscapes of meso- and racemic-PDL were examined using the Conformer–Rotamer Ensemble Sampling Tool and high-level quantum chemical calculations, generating 26 and 25 conformers, respectively. Five sets of rotational transitions were observed and assigned, with two attributed to meso-PDL and the remaining three attributed to racemic-PDL. Furthermore, tunneling splittings were observed for both meso-PDL conformers, and the nudged elastic band method was utilized to map the corresponding tunneling pathways and obtain tunneling barriers. To rationalize relative abundances of the observed conformers and the non-observation of other low-energy conformers, possible conversion pathways among meso-PDL conformers and racemic-PDL conformers were also explored. Finally, ten carbon-13 isotopologues, five from each of the lowest-energy meso- and racemic-PDL conformers, were detected in natural abundance and used to establish the corresponding geometries. These results offer valuable insights into the stereoisomeric behaviors and conformational preferences within flexible diols.
Sloshing response in rectangular water tanks under seismic actions considering resonant effects
Authors: Zhang Cong , Chen Yadong , Wan Hongmei , Jin Xin , Wang Baoliang , Li Baoliang , Wang Yue
Published: December 2024

This study explores the sloshing response of rectangular liquid tanks subjected to seismic excitations through a combination of large-scale shaking table tests and OpenFOAM-based numerical simulations, covering both resonant and non-resonant seismic conditions. The effects of seismic directionality on sloshing and the characteristics of sloshing behavior under resonant and non-resonant seismic actions are compared. Key findings include the following: (1) vertical seismic waves have minor impacts on sloshing response, contributing only 5.62% to the maximum sloshing height and 6.11% to the peak hydrodynamic pressure under resonant conditions, with the contributions increasing to 8.19%–9.21% for the maximum sloshing height and 10.22%–15.23% for peak hydrodynamic pressure under non-resonant conditions. (2) Significant sloshing waves can be induced even under low-amplitude resonant excitations. During resonant conditions, the water wave is dominated by low-order odd sloshing modes, whereas high-frequency seismic components and natural sloshing modes predominate under non-resonant conditions. (3) Correlation analysis reveals that when the dominant seismic frequency differs from the tank's natural frequency, the sloshing heights strongly correlate with the seismic waves. However, as the frequencies align, this correlation weakens and nonlinear sloshing behavior intensifies. (4) Westergaard's and Housner's formulas accurately predict the peak hydrodynamic pressure near the tank bottom under non-resonant conditions but significantly underestimate it under resonant conditions. A new formula is proposed for the peak hydrodynamic pressure calculation under resonance and validated through a real case study. The experimental data from the large-scale shaking table tests are expected to help address the deficiencies in the existing database for validating numerical models.
The α glycolipid rules the NKT cell TCR
Authors: Kronenberg Mitchell , Ascui Gabriel
Published: December 2024

In this issue of JEM, Hosono et al. (https://doi.org/10.1084/jem.20240728) characterize a putative self- glycolipid that engages the iNKT cell TCR when bound to CD1d. The expression and distribution of this compound helps to explain some of the unusual properties of invariant NKT cells.
APMP key comparison of luminous intensity (APMP.PR-K3.a): final report
Authors: Shitomi Hiroshi , Hui Liu , Xiaomei Jiang , Liu Wen-Chun , Lam Brenda , Suryani Dini , Jaiswal V K , Sharma Parag , Abdullah Mohd Nizam , Swift Neil , Leecharoen Rojana , Yuanjie Liu , Quan Cao Xuan , Rabe Irma , Toit Pieter du , Coetzee Elsie , Pepenene Refuoe , Sieberhagen Rheinhardt , Shafik Mohamed , EL-Sharkawy Fatma , EL-Maghraby Abeer
Published: December 2024

Main text

International key comparison on luminous intensity was organized by the Asia Pacific Metrology Programme (APMP), identified as APMP.PR-K3.a, and carried out with coordination by National Metrology Institute of Japan (NMIJ-AIST) as the pilot laboratory. In total, 13 national metrology institutes (NMIs) participated in the comparison. The linkage to the key comparison reference value (KCRV) of luminous intensity scale was provided through the result of the CCPR key comparison, CCPR-K3.a (1999), by NMIJ-AIST and National Institute of Metrology, China (NIM). In the comparison, a group of luminous intensity standard lamps were used as transfer standard lamps. The comparison was organized as star-type comparison (Participant - Pilot - Participant). Luminous intensity scale of each participant was compared with the KCRV through the measurement results of the transfer standard lamps and associated uncertainties, and the relationship with the KCRV were evaluated to declare its international equivalence. All the data analyses were performed in accordance with the CCPR guidelines.

This report provides the overview of the comparison, including measurement procedure, transfer standard lamps, data analysis, measurement results of all the participant NMIs and their uncertainties. The final result of the comparison is given as the degree of equivalence (DoE) of the participants obtained based on the difference from the KCRV determined in CCPR-K3.a (1999) and their stated uncertainties.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Comparison of blackbody for clinical infrared ear thermometers
Authors: Lu X , Bai C , Manoi A , Sasajima N , Yoo Y S , Wang L , Goh CH , Ko H Y , Cheung J , Wiriadinata H , Achmadi A , Samiudin N M , Othman H
Published: December 2024

Main text

A comparison of radiance temperature scales for clinical infrared ear thermometers have been performed successfully over the temperature range from 35.5 °C to 41.5 °C using one travelling blackbody in APMP. The radiance temperature of the travelling blackbody cavity has been compared directly to the standard blackbodies of the participating NMIs using ear thermometers with high resolutions and good short-term stabilities. There are some outliers in the results, but, in general, the radiance temperatures realized by the participant NMIs agree to well within ± 0.03 °C, which is agreeing with each other within the measurement uncertainties. The results also demonstrate comparable quality of the blackbody cavities recommended for the ear thermometer calibration in the ASTM, JIS, EN and CN standards. The results of this comparison can be used to underpin the Calibration and Measurement Capabilities (CMCs) of the participants, both for the calibration of ear thermometers and the ear thermometer blackbodies.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Clock synchronization and light-travel-time estimation for space-based gravitational-wave detectors
Authors: Niklas Reinhardt Jan , Hartwig Olaf , Heinzel Gerhard
Published: December 2024

Space-based gravitational-wave detectors, such as the Laser Interferometer Space Antenna (LISA), record interferometric measurements on widely separated satellites. Their clocks are not synced actively. Instead, clock synchronization is performed in on-ground data processing. It relies on measurements of the so-called pseudoranges, which entangle the interspacecraft light travel times (LTTs) with the clock desynchronizations between emitting and receiving spacecraft. For interspacecraft clock synchronization, we need to isolate the differential clock desynchronizations, i.e. disentangle the pseudoranges. This further yields estimates for the interspacecraft LTTs, which are required as delays for the laser frequency noise suppression via time-delay interferometry (TDI). Previous studies on pseudorange disentanglement apply various simplifications in the pseudorange modeling and the data simulation. In contrast, this article derives an accurate pseudorange model in the barycentric celestial reference system, complemented by realistic state-of-the-art LISA data simulations. Concerning pseudorange disentanglement, this leads to an a priori under-determined system. We demonstrate how on-ground orbit determinations, as well as onboard transmission and on-ground reception time tags of the telemetry data, can be used to resolve this degeneracy. We introduce an algorithm for pseudorange disentanglement based on a nonstandard Kalman filter specially designed for clock synchronization in systems where pseudorange measurements are conducted in different time frames. This algorithm achieves interspacecraft clock synchronization and LTT estimation with submeter accuracy, thus fulfilling the requirements of TDI.
Benchmark exact free vibration solutions of two-dimensional decagonal piezoelectric quasicrystal cylindrical shells
Authors: Su Xin , Yin Huilin , Nie Xueyang , Chen Lide , Sun Jiabin , Zhou Zhenhuan , Xu Xinsheng
Published: December 2024

Quasicrystalline materials with piezoelectric effects show significant potential for advancing actuators, sensors and energy harvesters. In this paper, the free vibration characteristics of two-dimensional decagonal piezoelectric quasicrystal cylindrical shells (PQCSs) are investigated in the framework of symplectic mechanics system. By introducing an original vector and its dual variable vector as the fundamental unknowns, the governing equations are reduced into a set of low-order ordinary differential equations system, thus the free vibration analysis is transformed into an eigenvalue problem within the symplectic space. By using the symplectic mathematics, the exact solutions for free vibration of PQCSs are finally obtained and expanded as a series of symplectic eigensolutions. Finally, accurate natural frequency and analytical vibration mode shapes for arbitrary classical boundary conditions are obtained simultaneously. The accuracy of the obtained solutions is verified by comparing with existing results in open literature. In addition, the effects of geometrical parameters, temperature rise, external voltage and coupling fields on the natural frequency and vibration mode shapes are investigated in numerical examples. Results indicate that the phason field exhibits significant influences on the natural frequencies and cannot be neglected in free vibration analysis of PQCSs. Furthermore, all the results can be served as benchmarks for the development of new analytical and numerical approaches.
Numerical study on ionic wind from pin to mesh with hole configuration under DC negative corona discharge
Authors: Chung Ji Hong , Ahn Tae Sung , Sohn Dong Kee , Ko Han Seo
Published: December 2024

This study explores the enhancement of ionic wind generation efficiency by incorporating a central hole in the mesh electrode under DC negative corona discharge conditions. Using numerical analysis techniques such as drift-diffusion equations and the Poisson equation, the mechanisms driving ionic wind generation were extensively analyzed. The characteristic Trichel pulses of negative corona discharge were examined by monitoring the variations in current with changes in applied voltage and central hole diameter. Particle image velocimetry experiments validated numerical analysis, showing good agreement between experimental and numerical results. The introduction of a central hole in the mesh electrode significantly reduced pressure drop and increased ionic wind velocity, addressing common problems of decreased momentum and increased frictional loss in mesh electrodes. This modification allows the ionic wind to flow more freely through the mesh electrode, enhancing overall efficiency by mitigating energy losses typically associated with mesh structures. Additionally, the study found that ionic wind velocity increased with rising voltage, showing variations in maximum velocity depending on hole size. The results suggest that optimizing central hole size could enhance the efficiency of ionic wind generation devices in various applications.
Dots and boxes algorithm for Peierls substitution: application to multidomain topological insulators
Authors: Díaz-Bonifaz Ricardo Y , Ramírez Carlos
Published: December 2024

Magnetic fields can be introduced into discrete models of quantum systems by the Peierls substitution. For tight-binding Hamiltonians, the substitution results in a set of (Peierls) phases that are usually calculated from the magnetic vector potential. As the potential is not unique, a convenient gauge can be chosen to fit the geometry and simplify calculations. However, if the magnetic field is non-uniform, finding a convenient gauge is challenging. In this work we propose to bypass the vector potential determination by calculating the Peierls phases exclusively from the gauge-invariant magnetic flux. The phases can be assigned following a graphic algorithm reminiscent of the paper and pencil game ‘dots and boxes’. We showcase the method implementation by calculating the interference phenomenon in a modified Aharonov–Bohm ring and propose a phase assignation alternative to the Landau gauge to reproduce the Half Integer Quantum Hall Effect in graphene. A non-uniform magnetic field case is addressed by considering a multi-domain Chern insulator to study the effects of domain walls in resistance and current quantization. It is found that adding decoherence and a finite temperature into the model results in quantized resistances that are in good agreement with experiments made with multi-domain intrinsic topological insulators.
Single-axis rotary inertial navigation system based on dual-IMU joint modulation
Authors: Lin Hongyi , Bian Hongwei , Zha Feng
Published: December 2024

At present, large and medium-sized ships are usually equipped with two or more sets of inertial navigation systems, but the inertial navigation systems operate independently of each other, and this approach only improves the reliability of the navigation information, and does not improve the accuracy of the navigation information. Aiming at the above problems, this paper proposes a dual-IMU joint modulation scheme, which ensures that there is an IMU in pause at any moment by reasonably designing the rotation strategy of the two sets of IMUs, so as to combine the data of the two IMUs in the time sequence. The scheme utilizes the symmetry of the rotational position to eliminate the error, and at the same time avoids the coupling error caused by the rotational motion of the IMUs, reduces the periodic error, and improves the navigation accuracy. Semi-physical simulation test results show that the improved joint modulation scheme has superior modulation effect on the device errors of inertial devices compared with the traditional rotational modulation scheme.
SnakeConv and SFC boosting precise segmentation on the crack of tunnel lining surface: based on DeepLabV3+ with improved Swin transformer V2
Authors: Li Longrong , Yang Yichen , Bian Mengqi , Li Zhipeng
Published: December 2024

Tunnel cracks pose a significant threat to structural integrity, potentially leading to localized collapse of the infrastructure. Traditional manual crack detection methods are prohibitively expensive, highlighting the need for an efficient and accurate automatic crack segmentation model. To address this challenge, we propose a novel crack segmentation model for subway tunnel lining surface based on the DeepLabV3+ architecture. In this model, we design an improved Swin transformer V2 Base (SwinV2*) as the backbone to enhance crack segmentation performance. Considering the tubular morphology of tunnel cracks, we introduce a snake convolution module to better capture their unique features. To prevent performance degradation when fusing shallow and deep features, we incorporate a spatial feature calibration module that facilitates feature alignment and grouping along the channel dimension. We assess our model’s effectiveness using thousands of crack images captured by the image acquisition system designed for subway tunnel surfaces. Experimental results show that our model achieves strong performance metrics: 68.96% IoU, 84.33% mIoU, 87.57% PA. Compared to the original DeepLabV3+, our approach demonstrates superior performance, with a 2.89% improvement in IoU, a 1.45% increase in mIoU and notably, a significant 10.39% improvement in PA.
Electrically-driven control of nanoscale chemical changes in amorphous complex oxide memristive devices
Authors: Román Acevedo Wilson , Aguirre Myriam H , Rubi Diego
Published: December 2024

In this paper we investigate the electrical response response of amorphous complex oxide memristors under different electrical stimulation. With the help of transmission electron microscopy and energy dispersive x-ray spectroscopy, we observed that those devices stimulated with voltage display strong cationic segregation at the nanoscale together with the partial crystallization of the oxide layer. On the other hand, devices stimulated with current maintain their amorphous character with no significative chemical changes. Our analysis also shows that current stimulation leads to a more stable memristive response with smaller cycle-to-cycle variations. These findings could contribute to the design of more reliable oxide-based memristors and underscore the crucial effect that has type of electrical stimulation applied to the devices has on their integrity and reliability.
Passivation of acceptors in GaN by hydrogen and their activation
Authors: Reshchikov M A , Andrieiev O , Vorobiov M , Ye D , Demchenko D O , McEwen B , Shahedipour-Sandvik F
Published: December 2024

GaN is an important semiconductor for energy-efficient light-emitting devices. Hydrogen plays a crucial role in gallium nitride (GaN) growth and processing. It can form electrically neutral complexes with acceptors during growth, which significantly increases the acceptor incorporation. Post-growth annealing dissociates these complexes and is widely utilized for activating Mg acceptors and achieving conductive p-type GaN. In this work, we demonstrate that other acceptors, such as C and Be, also form complexes with hydrogen similar to Mg. The effect of thermal annealing of GaN on photoluminescence (PL) was investigated. In samples moderately doped with Be, the BeGa-related yellow luminescence (YLBe) band intensity decreased by up to an order of magnitude after annealing in N2 ambient at temperatures T
ann = 400 °C–900 °C. This was explained by the release of hydrogen from unknown traps and the passivation of the BeGa acceptors. A similar drop of PL intensity at T
ann = 350 °C–900 °C was observed for the CN-related YL1 band in unintentionally C-doped GaN and also attributed to passivation of the CN acceptors by hydrogen released from unknown defects. In this case, the formation of the CNHi complexes was confirmed by the observation of the rising BL2 band associated with these complexes. At T
ann > 900 °C, both the YLBe and YL1 intensities were restored, which was explained by the removal of hydrogen from the samples. Experimental results were compared to the first principles calculations of complex dissociation and hydrogen diffusion paths in GaN.
The measurement of phenols with graphitic carbon fiber microelectrodes and fast-scan cyclic voltammetry
Authors: Abdullaeva Cam , Alyamni Nadiah , Jessen-Hegelbach Jackie , Zestos Alexander G
Published: December 2024

A phenol contains a six-membered, conjugated, aromatic ring bound to a hydroxyl group. These molecules are important in biomedical studies, aromatic food preparation, and petroleum engineering. Traditionally, phenols have been measured with several analytical techniques such as UV-VIS spectroscopy, fluorescence, liquid chromatography, and mass spectrometry. These assays provide for relatively high sensitivity and selectivity measurements, but they suffer from relatively low spatiotemporal resolution, low biocompatibility, long analysis time, high cost, and complex sample treatment. Recently, electrochemistry has served as a viable alternative to the measurement of phenols. In this study, we utilized carbon fiber microelectrodes (CFMEs) with fast-scan cyclic voltammetry for the sensitive and selective measurement of phenols. We tested four common phenolic compounds: phenol, 2-methylaminophenol (2-MAP), 4-methylaminophenol (4-MAP), and 3-hydroxybenzoic acid (3-HBA). We found that phenol, 2-MAP, 4-MAP, and 3-HBA were all partially adsorption and diffusion controlled to the surface of the CFMEs and that all four molecules could be detected with repeated injections. Structural differences led to varied sensitivities amongst the four phenols, and we were able to co-detect and differentiate the phenols in complex solutions with dopamine and serotonin. Lastly, we measured the phenols in simulated urine with a high percent recovery. These assays demonstrate enhanced electrochemical measurement of phenols, which will create more effective diagnostics for these complex molecules to help elucidate their mechanistic properties and ultimate significance in a biological context.
Analysis and circuit implementation of fractional-order memristive hyperchaotic system with enhanced memory
Authors: Qiu Le , Li Sai , Xiong Tao , Wang Liheng , Ding Zhixia
Published: December 2024

In this paper, based on the memory characteristics of fractional calculus, a new fractional-order memristor is proposed. Fractional-order memristor is a more accurate description of memristor, which has richer dynamic behavior and better memory performance. Which has a stronger memorizability compared to other fractional-order memristor by analyzing the pinched hysteresis loop area. Based on the above fractional-order memristor, a fractional-order memristive hyperchaotic circuit is designed, such system is analyzed by using the Lyapunov Exponents and the bifurcation diagrams.With the change of system parameters, the phase trajectory of the system expands and narrows, and the amplitude of the chaotic attractor also changes. In addition, double chaotic attractors and coexisting attractors are found under different parameters and initial values. Finally, the fractional order memristor and the fractional order memristor hyperchaos circuit are realized by analog circuit in Multisim.
Enhanced Clean Energy Generation through Capacitive Electrode Utilization in Reverse Electrodialysis
Authors: Alghamdi Eman A. , Sai Refka , Alzahrani Khalid E.
Published: December 2024

In this study, we explore the potential of a novel energy generation method, Capacitive Reverse Electrodialysis (CRED), which combines seawater and river water to produce electricity. CRED integrates a membrane stack, similar to Reverse Electrodialysis (RED), with capacitive electrodes. The salinity gradient between the two water sources generates a potential difference across ion-selective membranes, enabling sustainable energy production. Unlike traditional RED systems that rely on redox reactions, CRED utilizes capacitive electrodes, preventing saturation and enhancing system longevity by periodically switching the water flows and reversing the direction of the electric current. The larger membrane stack in CRED allows for greater charge accumulation than previous capacitive mixing methods, leading to higher voltage and more efficient energy capture. As a result, CRED achieves a power density approximately ten times higher than previous capacitive power extraction trials, reaching performance levels comparable to or exceeding those of conventional RED systems with redox-based electrodes. Overall, CRED demonstrates a promising alternative to traditional energy generation methods, offering a stable, secure, environmentally friendly, and high-performance solution for harnessing energy from the mixing of saltwater and freshwater.
A simple formula for the critical temperature of D-dimensional Ising models
Authors: Ostilli Massimo
Published: December 2024

We propose a simple equation for the critical temperature (CT) of D-dimensional Ising models (on squared or not squared lattices). When 2 < D < ∞, these models have no exact solution and even the simpler problem of locating the CT analytically remains a formidable task. The mean-field as well as the belief-propagation methods provide approximations that work only for large D, remaining quite unsatisfactory for D ≤ 4. Our simple equation represents a sort of ‘finite-dimensional’ generalization of such approaches. It provides a reasonable approximation for D = 2 and works pretty well for D ≥ 3 where, in general, outperforms other purely analytical methods. The equation is derived by using duality relations and heuristic arguments.
Optimizing perovskite solar cells: simulating the impact of Bi2Te3 and BiTeI interlayers
Authors: Dagar Anju , Batra Yogita
Published: December 2024

Perovskite solar cells (PSCs) have emerged as a promising technology for efficient and cost-effective solar energy conversion. To further enhance their performance and stability, integrating interlayer (IL) between the perovskite absorber and transport layers is paramount. In this study, we investigated and compared the performance of two distinct IL materials, Bi2Te3 (BT) and BiTeI (BTI), in PSCs. The ILs were integrated between the perovskite layer and electron/hole transport layers to modulate charge transport and recombination dynamics. Our results reveal that both BT and BTI ILs can effectively passivate the surface defects in the perovskite absorber, leading to reduced non-radiative recombination and improved open-circuit voltage (VOC) in the solar cells. The thickness of the BT and BTI IL was varied from 50 nm to 300 nm to study the effect of thickness on the efficiency of the PSC. IL defect density and interface defect densities were also studied in both the PSCs.
CMB implications of multi-field axio-dilaton cosmology
Authors: Smith Adam , Mylova Maria , Brax Philippe , van de Bruck Carsten , Burgess C.P. , Davis Anne-Christine
Published: December 2024

Axio-dilaton models are among the simplest scalar-tensor theories that contain the two-derivative interactions that naturally compete at low energies with the two-derivative interactions of General Relativity. Such models are well-motivated as the low energy fields arising from string theory compactification. We summarize these motivations and compute their cosmological evolution, in which the dilaton acts as dark energy and its evolution provides a framework for dynamically evolving particle masses. The derivative axion-dilaton couplings play an important role in the success of these cosmologies. We derive the equations for fluctuations needed to study their implications for the CMB anisotropy, matter spectra and structure growth. We use a modified Boltzmann code to study in detail four benchmark parameter choices, including the vanilla Yoga model, and identify couplings that give viable cosmologies, including some with surprisingly large matter-scalar interactions. The axion has negligible potential for most of the cosmologies we consider but we also examine a simplified model for which the axion potential plays a role, using axion-matter couplings motivated by phenomenological screening considerations. We find such choices can also lead to viable cosmologies.
SOLEDGE3X full vessel plasma boundary simulations of ITER non-active phase plasmas
Authors: Rivals N. , Tamain P. , Marandet Y. , Bonnin X. , Park J.-S. , Bufferand H. , Pitts R.A. , Falchetto G. , Yang H. , Ciraolo G.
Published: December 2024

The onset of detachment in the ITER machine is analyzed in this work through the help of 2D-axisymmetric boundary plasma simulations with the SOLEDGE3X-EIRENE code, which features a numerical domain for the plasma solver extending up to the first wall. The plasma boundary is computed in scenarios from the first non-active phase of ITER, in pure H and at 20 MW. This set of simulations is used in two aspects: first, to study the plasma detachment in the divertor, and second, the plasma conditions, fluxes, and beryllium erosion at the first wall. Here, the code results are also compared to those obtained with the well-established SOLPS-ITER code, which includes a plasma numerical domain only covering the main SOL. Results show an increase in the SOL width λ

q
with increasing density, and a detailed analysis is carried out, for the first time, on each of the different plasma-neutral interactions in the code’s physics model in EIRENE. The gross beryllium erosion rates of first wall panels are estimated from 2D simulations, with the aim of assessing their sensitivity to two parameters: the divertor density regime, and the presence of density shoulders in the far-SOL formed by enhanced perpendicular transport at this location. The erosion contributions from neutrals and ions are considered in each case, and the charge-exchange atoms fluxes and energy distributions are provided, highlighting the two atom populations (cold and charge-exchange).
Design of 3D equilibria and coils for steady-state operation of tokamaks
Authors: Liang Yihui , Zhou Yao , Dong Fanghao , Zhu Caoxiang , Yu Guodong , Zhao Yuansheng , Dong Ge
Published: December 2024

Inspired by the respective advantages of tokamaks and stellarators, we propose a quasi-axisymmetric (QA) tokamak-stellarator hybrid concept as a steady-state operation mode of standard tokamaks. Using stellarator optimization tools, we obtain compact 3D equilibria with good QA and sufficient (∼20%) rotational transform generated by external coils to replace current drive, with the rest (∼80%) generated self-consistently by the bootstrap current. The equilibria can be supported by 3D saddle coils that are compatible with typical tokamak coils and reasonably feasible from engineering perspectives. We consider and compare designs with either high-field-side or low-field-side shaping, and find that the latter is favorable for coil optimization but unfavorable for generating rotational transform and achieving good QA. These results highlight a relatively unexplored region in the space of toroidal fusion configurations.
Advancing tritium self-sufficiency in fusion power plants: insights from the BABY experiment
Authors: Delaporte-Mathurin Rémi , Goles Nikola , Ball John , Dunn Collin , Edwards Emily , Ferry Sara , Lamere Edward , Lanzrath Andrew , Leccacorvi Rick , Meschini Samuele , Peterson Ethan , Segantin Stefano , Vieira Rui , Whyte Dennis , Zhou Weiyue , Woller Kevin
Published: December 2024

In the pursuit of fusion power, achieving tritium self-sufficiency stands as a pivotal challenge. Tritium breeding within molten salts is a critical aspect of next-generation fusion reactors, yet experimental measurements of Tritium Breeding Ratio (TBR) have remained elusive. Here we present the results of the Build A Better Yield blanket experiment, which represents a pioneering effort in tritium research by utilizing high-energy (14 MeV) neutron irradiation of molten salts, a departure from conventional low-energy neutron approaches. Using a small-scale (100 ml) molten salt tritium breeding setup, we not only simulated, but also directly measured a TBR (

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). This innovative approach provides crucial experimental validation, offering insights unattainable through simulation alone. Moreover, our findings reveal a surprising outcome: tritium was predominantly collected as HT, contrary to the expected TF. This underscores the complexity of tritium behavior in molten salts, highlighting the need for further investigation. This work lays the foundation for a more sophisticated experimental setup, including increasing the volume of the breeder, enhancing neutron detection, and refining tritium collection systems. Such improvements are crucial for advancing our understanding of fusion reactor feasibility and paving the way for future experiments.
Influence of mechanical characteristics of materials of threaded connections of oil and gas downhole equipment on their fatigue life
Authors: Kopei V B , Onysko O R , Kopei I B , Panchuk V G , Bukatka Y S , Goroshko A V
Published: December 2024

Threaded connections of downhole oil and gas equipment such as tool joints of drill pipes and sucker rod connections operate under difficult conditions of significant cyclic loading and a corrosive environment. This often leads to material fatigue and parts failure. Therefore, the design of such threaded connections requires accurate methods for calculating fatigue life. Using an improved finite element analysis technique in Abaqus/CAE and fe-safe, which takes into account maximum plastic deformation in the first steps of the simulation, the influence of the mechanical characteristics of the materials of these threaded connections on their fatigue life was investigated. An increase in the ductility of the pin or box material leads to equalization of loads along the thread and an increase in the fatigue safety factor, but only if the fatigue strength of this material is sufficient. An additional increase in fatigue life can be achieved by optimal plastic pre-deformation of the connection under a high axial external load. The results prove that the fatigue life of these threaded connections can be significantly improved without optimizing their geometric parameters.
Phase stability compliancy testing of a White Rabbit based solution for the LHC RF and Timing Distribution Backbone upgrade
Authors: Hazell P. , Baron S. , Gousiou E. , Hagmann G. , Gill J. , Lipinski M. , Genoud Q. , Gingold T. , Wlostowski T.
Published: December 2024

The LHC RF and Timing Distribution Backbone is being upgraded for the HL-LHC. A White Rabbit technology solution for the generation and the distribution of the RF, similar to the system currently employed in SPS, is being considered. To verify its suitability from a phase stability perspective, an investigation was conducted on a proof-of-concept system. The requirement for the end-nodes is ± 1 degree of the 200 MHz SPS RF frequency. The key figure of merit to check compliancy is peak-peak phase variation which must be < 28 ps. The compliance tests campaign will be described and results presented.
Minimizing inconsistencies in gray values in small field-of-view dental computed tomography by modulating reconstruction filter intensity: simulation study
Authors: Kim Woosung , Shim Jiyong , Jeon Duhee , Lim Younghwan , Lee Soohyun , Kim Kyuseok , Park Chulkyu , Cho Hyosung
Published: December 2024

Small field-of-view (FOV) cone-beam computed tomography (CBCT), which employs low-cost,
small-area flat-panel detectors, is often used in dental CT where only a limited volume of an
examined object is reconstructed using the standard filtered-backprojection algorithm. However,
when examining with a small FOV, the surrounding structures located outside the FOV exacerbate the
inhomogeneity of the inherent distribution of gray values (GVs) in the reconstructed CBCT
volume. To address this issue, this study presents an effective method to minimize the
inconsistencies in GVs in small FOV CBCT images by modulating reconstruction filter (ramp filter)
intensity. To verify the efficacy of the proposed method, a feasibility study was conducted via a
simulation using three-dimensional numerical mouth phantoms without metal insert and with metal
inserts as highly attenuating dental materials. The mean GVs of the innermost FOV without
correction were 60.3 and 63.1 for the cases of no metal and two metal inserts, respectively, which
were approximately 7.8% and 6.5% greater than those of the corresponding reference FOVs. In
contrast, the mean GVs with correction for all target FOVs were very close (<0.1%) to that of
the reference FOV, indicating the efficacy of the proposed method. Consequently, small FOV dental
CT images with good homogeneity of the GV distribution were successfully obtained using the
proposed method, which is critical, particularly for assessing bone density in dental implantation
surgery plan.
Hybrid near and far field electrospinning of PVDF-TrFE/BaTiO3 scaffolds: morphology and osteoblast-like cell responses
Authors: Ribeiro Larissa Mayra Silva , Berniak Krzysztof , Sukumaran Sunija , Gimenes Rossano , Stachewicz Urszula
Published: December 2024

Scaffolds are of great interest in tissue engineering associated with regenerative medicine owing to their ability to mimic biological structures and provide support for new tissue formation. Several techniques are used to produce biological scaffolds; among them, far-field electrospinning (FFES) process is widely used due to its versatility in producing promising structures similar to native tissues owing to the electrospun nanofibers. On the other hand, near-field electrospinning (NFES) has been investigated due to the possibility of creating scaffolds with suitable architecture for their use in specific biological tissues. Thus, we investigated the potential of the electrospun scaffolds prepared using both techniques FFES and NFES, with tailored properties to mimic bone tissue native matrix and enhance the cell response. We produced scaffolds with the piezoelectric poly(vinylidene fluoride-trifluoroethylene) combined with BaTiO3 nanoparticles. Hence, the properties of both scaffolds were evaluated in terms of crystallinity and cell behavior, such as adhesion, proliferation and cell viability. Microstructure properties showed good thermal stability, similar crystallinity (∼65%) and a β-phase content of ∼40% for both scaffolds. For biological tests, MG-63 osteoblast-like cells were used, and for NFES scaffolds, we noted that the proliferation and cell alignment followed the fiber pattern and created a bridge between adjacent fibers. In contrast, cells spread and proliferated randomly on the surface of the FFES scaffold. Despite the differences in cell behavior, both scaffolds showed good biocompatibility in terms of functional scaffolds with suitable characteristics for use in the area of tissue regeneration.
Internal climate variability modulates decadal changes in ocean anthropogenic carbon storage
Authors: Olivarez Holly C , Lovenduski Nicole S , Maroon Elizabeth , Müller Jens D , Fay Amanda R , Krumhardt Kristen M , Levy Michael N , Lindsay Keith , McKinley Galen A , Rader Jamin K
Published: December 2024

The ocean removes man-made (anthropogenic) carbon from the atmosphere and thereby mitigates climate change. Observations from global hydrographic surveys reveal the spatial and temporal evolution of the ocean inventory of anthropogenic carbon and suggest substantial decadal variability in historical storage rates. Here, we use a 100-member ensemble of an Earth system model to investigate the influence of external forcing and internal climate variability on historical changes in ocean anthropogenic carbon storage over 1994 to 2014. Our findings reveal that the externally forced, decadal changes in storage are largest in the Atlantic (2–4 mmol m−3 decade−1) and positive nearly everywhere. Internal climate variability modulates regional ocean anthropogenic carbon storage trends by up to 10 mmol m−3 decade−1. The influence of internal climate variability on decadal storage changes is most prominent at depths of ∼300 m and at the edges of the subtropical gyres. Internal variability in anthropogenic carbon in the extratropics has high spectral power on decadal to multi-decadal timescales, indicating that the approximately decadal repetitions of hydrographic surveys may produce storage change estimates that are heavily influenced by internal climate variability.