bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine-learning nowcasting of the Atlantic Meridional Overturning Circulation
Authors: Zhai Zheng-Meng , Moradi Mohammadamin , Panahi Shirin , Wang Zhi-Hua , Lai Ying-Cheng
Published: July 2024

The Atlantic Meridional Overturning Circulation (AMOC) is a significant component of the global ocean system, which has so far ensured a relatively warm climate for the North Atlantic and mild conditions in regions, such as Western Europe. The AMOC is also critical for the global climate. The complexity of the dynamical system underlying the AMOC is so vast that a long-term assessment of the potential risk of AMOC collapse is extremely challenging. However, short-term prediction can lead to accurate estimates of the dynamical state of the AMOC and possibly to early warning signals for guiding policy making and control strategies toward preventing AMOC collapse in the long term. We develop a model-free, machine-learning framework to predict the AMOC dynamical state in the short term by employing five datasets: MOVE and RAPID (observational), AMOC fingerprint (proxy records), and AMOC simulated fingerprint and CESM AMOC (synthetic). We demonstrate the power of our framework in predicting the variability of the AMOC within the maximum prediction horizon of 12 or 24 months. A number of issues affecting the prediction performance are investigated.
Quantum advantage of one-way squeezing in weak-force sensing
Authors: Wang Jie , Zhang Qian , Jiao Ya-Feng , Zhang Sheng-Dian , Lu Tian-Xiang , Li Zhipeng , Qiu Cheng-Wei , Jing Hui
Published: July 2024

Cavity optomechanical (COM) sensors, featuring efficient light–motion couplings, have been widely used for ultrasensitive measurements of various physical quantities ranging from displacements to accelerations or weak forces. Previous works, however, have mainly focused on reciprocal COM systems. Here, we propose how to further improve the performance of quantum COM sensors by breaking reciprocal symmetry in purely quantum regime. Specifically, we consider a spinning COM resonator and show that by selectively driving it in opposite directions, highly nonreciprocal optical squeezing can emerge, which in turn provides an efficient way to surpass the standard quantum limit which is otherwise unattainable for the corresponding reciprocal devices. Our work confirms that breaking reciprocal symmetry, already achieved in diverse systems well beyond spinning systems, can serve as a new strategy to further enhance the abilities of advanced quantum sensors, for applications ranging from testing fundamental physical laws to practical quantum metrology.
Shunt-free cryogenic memory using ferromagnetic insulator-based Josephson junctions
Authors: Sharma Pramod K. , Pal Avradeep
Published: July 2024

Magnetic Josephson junctions are the preferred candidate devices for designing fast and scalable cryogenic memory elements. This is especially the case for rapid single-flux quantum-based superconducting electronics, where the speed mismatch between logic and memory elements have remained a long-standing challenge. In this Letter, we demonstrate a simple tri-layer Josephson memory device using ferromagnetic insulating (FI) GdN-based S/FI/S vertical mesa-type junctions, with reliable nonvolatile memory operation without the need of a shunt resistor at 4.2 K. The characteristic frequency of our devices is approximately 90 GHz, corresponding to an IcRn product of 177 μV. We demonstrate a thorough study of the parameter spaces required for designing these devices and identify the scope for future improvements that can lead to further miniaturization and higher operating speed of these devices.
Anomalies of solute transport in flow of shear-thinning fluids in heterogeneous porous media
Authors: Omrani Sina , Green Christopher , Sahimi Muhammad , Niasar Vahid
Published: July 2024

Solute transport and mixing in heterogeneous porous media are important to many processes of practical applications. Most of the previous studies focused on solute transport in flow of Newtonian fluids, whereas there are many processes in which the phenomenon takes place in flow of a non-Newtonian fluid. In this paper, we develop a computational approach to evaluate and upscale dispersion of a solute in flow of a shear-thinning (ST) fluid in a heterogeneous porous medium. Our results indicate that the dispersivity is a non-monotonic function of the Péclet number and the shear rate, and this behavior is accentuated by the heterogeneity of the pore space and spatial correlations between the local permeabilities. As a result, solute transport in ST fluids deviates significantly from the same phenomenon in Newtonian fluids. Moreover, the shear-dependence of the dispersivity strongly influences the fate of solute transport in porous media at large length scales, including larger effluent concentration at the breakthrough point, which also occurs much faster than Newtonian fluids. To provide further evidence for the numerical findings, we compare dispersion in flow of a power-law fluid in a single tube with the same in a bundle of such tubes. Our results emphasize the shortcomings of the current theories of dispersion to account for the role of fluid rheology in solute mixing and spreading.
Electrical conductivity of copper in the low temperature region of warm dense matter
Authors: Park Sungbin , Chi Hsiao-Chien , Lee Hakmin , Cho Jongweon , Chung Kyoung-Jae
Published: July 2024

In this study, electrical conductivity of copper in the low temperature part of a warm dense matter regime is investigated utilizing underwater electrical wire explosion. Specifically, for the vapor/plasma region with a density of ∼0.01 normal density, temperature up to 10 kK, and the liquid–vapor two-phase region below the binodal curve, the electrical conductivity of copper is measured as a function of density and temperature by means of shadowgraph imaging, spectroscopy, and electrical measurements. In this region, anomalous temperature dependence and characteristics originated from a phase transition are found. Based on the careful analysis of experiments and model calculations, it is revealed that bound electrons, in addition to free electrons, contribute significantly to the electrical conductivity in the vapor/plasma region, and that the associated phase transition kinetics play a substantial role in adequately describing the behavior in the liquid–vapor two-phase region. An improved electrical conductivity model emerging from our combined experimental and theoretical study that accounts for the characteristics in the low temperature regime of the warm dense matter is presented.
Quantitative time-resolved diagnostics of electric field dynamics during individual plasma breakdown events using burst laser pulse electric field induced second harmonic generation
Authors: Chen Timothy Y. , Liu Ning , Zhong Hongtao , Mao Xingqian , Goldberg Benjamin M. , Kliewer Christopher J. , Kolemen Egemen , Ju Yiguang
Published: July 2024

In plasma discharges, the acceleration of electrons by a fast varying electric field and the subsequent collisional electron energy transfer determines the plasma dynamics, chemical reactivity, and breakdown. Current in situ electric field measurements require reconstruction of the temporal profile over many observations. However, such methods are unsuitable for non-repetitive and unstable plasmas. Here, we present a method for creating “movies” of dynamic electric fields in a single acquisition at sample rates of 500 × 106 fps. This ultrafast diagnostic was demonstrated in radio frequency electric fields between two parallel plates in air, as well as in Ar nanosecond-pulsed single-sided dielectric barrier discharges.
Calculating absorption and fluorescence spectra for chromophores in solution with ensemble Franck–Condon methods
Authors: Khanna Ajay , Shedge Sapana V. , Zuehlsdorff Tim J. , Isborn Christine M.
Published: July 2024

Accurately modeling absorption and fluorescence spectra for molecules in solution poses a challenge due to the need to incorporate both vibronic and environmental effects, as well as the necessity of accurate excited state electronic structure calculations. Nuclear ensemble approaches capture explicit environmental effects, Franck–Condon methods capture vibronic effects, and recently introduced ensemble-Franck–Condon approaches combine the advantages of both methods. In this study, we present and analyze simulated absorption and fluorescence spectra generated with combined ensemble-Franck–Condon approaches for three chromophore–solvent systems and compare them to standard ensemble and Franck–Condon spectra, as well as to the experiment. Employing configurations obtained from ground and excited state ab initio molecular dynamics, three combined ensemble-Franck–Condon approaches are directly compared to each other to assess the accuracy and relative computational time. We find that the approach employing an average finite-temperature Franck–Condon line shape generates spectra nearly identical to the direct summation of an ensemble of Franck–Condon spectra at one-fourth of the computational cost. We analyze how the spectral simulation method, as well as the level of electronic structure theory, affects spectral line shapes and associated Stokes shifts for 7-nitrobenz-2-oxa-1,3-diazol-4-yl and Nile red in dimethyl sulfoxide and 7-methoxy coumarin-4-acetic acid in methanol. For the first time, our studies show the capability of combined ensemble-Franck–Condon methods for both absorption and fluorescence spectroscopy and provide a powerful tool for simulating linear optical spectra.
Laser-induced spectral tuning of single quantum dots embedded into microposts cladded with HfO2
Authors: Mudi P. , Shih C.-W. , Holzer M. , Elhajhasan M. , Limame I. , Hüllen I. , Palekar C. C. , Banerjee S. , Koulas-Simos A. , Gaur K. , Deshpande V. , Dubourdieu C. , Callsen G. , Reitzenstein S.
Published: July 2024

Our work investigates the precise tuning of InGaAs quantum dots (QDs) embedded into microposts by leveraging HfO2 crystallization-induced micro-strain via laser annealing. We investigate the efficacy of laser annealing power as a parameter for spectral control, achieving a notable blue shift of QD emissions of up to 5 meV. Through comprehensive Raman thermometry, we reveal consistent dependencies in laser-induced heating relative to micropost diameter, with larger microposts exhibiting superior heat dissipation capabilities and smaller tuning range. For instance, a 5.0 μm micropost demonstrates a maximum local temperature increase of 260 K at 1.82 mW of annealing power, compared to 435 K for a 1.1 μm diameter micropost under the same conditions. By correlating local temperatures derived from the longitudinal optical phonon linewidth of the Raman spectra, with QD emission line blue shift at specific laser powers, the tunability across differing post diameters is studied. Our findings underscore the potential of strain-tuning QDs through laser-induced HfO2 crystallization, offering avenues for scalable resonant single-photon sources applicable in superradiance and multi-photon interference scenarios.
Projection-based reduced order modeling of multi-species mixing and combustion
Authors: Ni Chenxu , Ding Siyu , Li Jiabin , Chu Xu , Ren Zhuyin , Wang Xingjian
Published: July 2024

High-fidelity simulations of mixing and combustion processes are computationally demanding and time-consuming, hindering their wide application in industrial design and optimization. This study proposes projection-based reduced order models (ROMs) to predict spatial distributions of physical fields for multi-species mixing and combustion problems in a fast and accurate manner. The developed ROMs explore the suitability of various regression methods, including kriging, multivariate polynomial regression (MPR), k-nearest neighbors (KNN), deep neural network (DNN), and support vector regression (SVR), for the functional mapping between input parameters and reduced model coefficients of mixing and combustion problems. The ROMs are systematically examined using two distinct configurations: steam-diluted hydrogen-enriched oxy-combustion from a triple-coaxial nozzle and fuel-flexible combustion in a practical gas-turbine combustor. The projected low-dimensional manifolds are capable of capturing important combustion physics, and the response surfaces of reduced model coefficients present pronounced nonlinear characteristics of the flowfields with varying input parameters. The ROMs with kriging present a superior performance of establishing the input–output mapping to predict almost all physical fields, such as temperature, velocity magnitude, and combustion products for both test problems. The accuracy of DNN is less encouraging owing to the stringent requirement on the size of training database. KNN performs well in the region near the design points but its effectiveness diminishes when the test points are distant from the sampling points, whereas SVR and MPR exhibit large prediction errors. For the spatial prediction at unseen design points, the ROMs achieve a prediction time of up to eight orders of magnitude faster than conventional numerical simulations, rendering an efficient tool for the fast prediction of mixing and combustion fields and potentially an alternative of a full-order numerical solver.
Coal measure gas resources matter in China: Review, challenges, and perspective
Authors: Li Li , Ma Shengming , Liu Xin , Liu Jun , Lu Yang , Zhao Peng , Kassabi Nadhem , Hamdi Essaieb , Elsworth Derek
Published: July 2024

Achieving the dual carbon goals of peaking by 2030 and neutrality by 2060 is significantly aided by the growth of coal measure gas research and development, especially for China to optimize its primary energy consumption. We critically review the distribution, geological characteristics, methods of liberation and then recovery by hydraulic fracturing of coal measure gas in China and present a roadmap to optimize this recovery. The gas-bearing system is the focus of this recovery, but this system is embedded within its sedimentary environment and modulated by tectonic and hydrogeological controls that affect gas exploration and recovery. However, to improve the development of coal measure gas in China, bottleneck problems remain to be solved, such as accurately predicting reservoir behavior in dessert regions, optimizing well patterns, and deploying optimal horizontal well trajectories. Additionally, the technology breakthroughs on deep co-production of coal measure gas, automatic fracturing and intelligent drainage are imminent. Basically, developing new techniques and conducting improved geological surveys are essential to ensure the sustainable supply of coal measure gas resource. Thus, this review presents a comprehensive introduction to coal measure gas resources in China, of utility to academic researchers and engineers in enhancing the understanding of the current situation and in projecting future development.
Proton gated oxide neuromorphic transistors with temperature-sensitive thermochromic function
Authors: Huang Xin , Zhou Si Yuan , Chen Xin Li , Huang You Jie , Wang Wei Sheng , Li Yan , Xiao Hui , Zhu Li Qiang
Published: July 2024

Temperature is always one of the most important factors that critically affects the electrical performance of devices. In the present work, the thermochromic function has been realized on oxide neuromorphic transistors gated by a chitosan based electrolyte mixed with temperature-sensitive thermochromic powder. Except for extremely strong proton gating effects, the device exhibits temperature-sensitive thermochromic activities with good electrical performance. It also demonstrates typical synaptic functions at different temperatures, mimicking heat pain sensation activities. Additionally, a high recognition accuracy of ∼93.80% for MNIST handwritten digits is obtained at different temperatures, indicating good stabilities for neuromorphic computing. The present work opens up interesting idea for bionic cognitive electronic skin and bionic thermochromic cognitive platforms.
Micro-transfer printed high-speed InP-based electro-absorption modulator on silicon-on-insulator
Authors: Moynihan Owen , Ghosh Samir , Chugh Shivangi , Thomas Kevin , O'Callaghan James , Atar Fatih Bilge , Roycroft Brendan , Patel Romil , Antony Cleitus , Townsend Paul , Pelucchi Emanuele , Corbett Brian
Published: July 2024

A high-speed InP-based electro-absorption modulator (EAM) on 220 nm silicon-on-insulator (SOI) is designed, fabricated, and measured. The III–V device is heterogeneously integrated to the SOI using transfer printing, with direct bonding. The printing accuracy of the device was within ±0.5 μm. This design evanescently couples light between the III–V waveguide and the SOI via a taper region in the InP ridge for high transmission. This method is a flexible and robust method of transferring an InP EAM to SOI, where multiple device variations have been transferred. At 1550 nm, the printed EAM has a measured electrical bandwidth of up to 40 GHz, an extinction ratio (ER) of 30 dB from 0 to −6 V, and an insertion loss of 6.5 dB, which reduces with longer wavelengths. An ER of 25 dB is obtained over a spectral bandwidth of 30 nm with biasing to −8 V. Open-eye diagrams were measured up to 50 Gbps in a back-to-back measurement. This device is suitable for applications in high-speed communications and sensing, leveraging the added advantage of III–V absorption modulation on a silicon photonics platform.
Theoretical simulation of time-related electrical performance of 63NiO/ZnO integrated betavoltaic battery
Authors: Zhang Yu , Lu Jingbin , Yuan Xinxu , Li Xiaoyi , Liu Xinrui , Li Qingyang , Liu Yuxin , Li Haolin , Cui Qiming , Tian Fubo , Liang Lei , Zeng Yugang , Han Genquan
Published: July 2024

The temporal electrical performance of a 63NiO/ZnO integrated betavoltaic battery is examined. Utilizing first-principles calculations combined with Monte Carlo simulations, we study the energy band structure and density of states of 63NiO, particularly when 63Ni undergoes a 12.5% decay. Our findings reveal that, when the 63NiO layer is 4 μm thick, the decay's impact is akin to substitution doping. Leveraging this insight, we employed Silvaco ATLAS software to simulate the time-dependent short-circuit current, open-circuit voltage, maximum output power, and energy conversion efficiency of the 63NiO/ZnO integrated betavoltaic battery. These results were compared with those of a NiO/ZnO separate betavoltaic battery. At 6.93 years, the maximum output power of the integrated and separate devices was found to be 10.19 and 9.77 nW/cm2, respectively, corresponding to 8.67% and 88.79% of their initial values. Notably, prior to this point, the integrated device exhibited significantly superior performance; at 4.58 years, it demonstrated 2.28 times higher maximum output power compared to the separate device, followed by only a slight difference in performance thereafter.
Growth-adjusted CiteScore
Authors: Phan-Thien Nhan , Giacomin Alan Jeffrey , Kanso Mona A. , Pan Dingyi , Zatloukal Martin
Published: July 2024

CiteScore is a measure of the impact of a journal on the scholarly literature over its previous four calendar years. It is the ratio of the total citations to the total journal publications over this interval. For a growing journal, the number of publications in the second and subsequent years of that interval exceeds that in the first year. The more rapid the growth, the greater these differences. Publications in the first year are, of course, older than those of the second year and continue to attract citations in the second and subsequent years. Thus, the increase in citations cannot keep pace with the increase in publications, and positive journal growth skews the CiteScore metric downward. We explore this CiteScore growth penalty and arrive at a simple way to growth-adjust the CiteScore.
Optimising disaster response: opportunities and challenges with Uncrewed Aircraft System (UAS) technology in response to the 2020 Labour Day wildfires in Oregon, USA
Authors: Kang Dae Kun , Fischer Erica , Olsen Michael J. , Adams Julie A. , O’Neil-Dunne Jarlath
Published: July 2024

Background The expanding use of Uncrewed Aircraft System (UAS) technology in disaster response shows its immense potential to enhance emergency management. However, there is limited documentation on the challenges and data management procedures related to UAS operation. Aims This manuscript documents and analyses the operational, technical, political, and social challenges encountered during the deployment of UAS, providing insights into the complexities of using these technologies in disaster situations. Methods This manuscript documents and analyses the operational, technical, political, and social challenges encountered during the deployment of UAS, providing insights into the complexities of using these technologies in disaster situations. Key results UAS technology plays a significant role in search and rescue, reconnaissance, mapping, and damage assessment, alongside notable challenges such as extreme flying conditions, data processing difficulties, and airspace authorisation complexities. Conclusions The study concludes with the need for updated infrastructure standards, streamlined policies, and better coordination between technological advancements and political processes, emphasising the necessity for reform to enhance disaster response capabilities. Implications The findings of this study inform future guidelines for the effective and safe use of UAS in disaster situations, advocating for a bridge between state-of-the-art UAS research and its practical application in emergency response.
Longitudinal stability of individual brain plasticity patterns in blindness
Authors: Amaral Lénia , Thomas Peyton , Amedi Amir , Striem-Amit Ella
Published: July 2024

The primary visual cortex (V1) in blindness is engaged in a wide spectrum of tasks and sensory modalities, including audition, touch, language, and memory. This widespread involvement raises questions regarding the constancy of its role and whether it might exhibit flexibility in its function over time, connecting to diverse network functions specific to task demands. This would suggest that reorganized V1 assumes a role like multiple-demand system regions. Alternatively, varying patterns of plasticity in blind V1 may be attributed to individual factors, with different blind individuals recruiting V1 preferentially for different functions. In support of this, we recently showed that V1 functional connectivity (FC) varies greatly across blind individuals. But do these represent stable individual patterns of plasticity, or are they driven more by instantaneous changes, like a multiple-demand system now inhabiting V1? Here, we tested whether individual FC patterns from the V1 of blind individuals are stable over time. We show that over two years, FC from the V1 is unique and highly stable in a small sample of repeatedly sampled congenitally blind individuals. Further, using multivoxel pattern analysis, we demonstrate that the unique reorganization patterns of these individuals allow decoding of participant identity. Together with recent evidence for substantial individual differences in V1 connectivity, this indicates that there may be a consistent role for V1 in blindness, which may differ for each individual. Further, it suggests that the variability in visual reorganization in blindness across individuals could be used to seek stable neuromarkers for sight rehabilitation and assistive approaches.
Efficient strategy for frequency design and bandwidth extension of curved piezoelectric ultrasonic micromachined transducers
Authors: Li Hao , Hu Xiaofan , Xu Xingli , Ma Yongquan , Yu Chenyang , Wei Wei , Niu Pengfei
Published: July 2024

This article proposes an efficient analytical model and strategy for designing curved piezoelectric micromachined ultrasonic transducers (curved PMUTs). The model is developed based on the Donnell–Mushtari–Vlasov theory and the equivalent single layer method, and validated through finite element analysis. Utilizing the model, we further analyze the diaphragm’s vibration modes and key design parameters. The proposed strategy is centered on 2 design equations, facilitating the rapid design of devices at any frequency through parametric sweeps. Furthermore, to minimize bandwidth loss, we employ the merging of adjacent vibration modes to broaden the bandwidth. Using the proposed method for modes merging, we have effortlessly designed devices with operating frequencies of 2.15 MHz, 6.3 MHz, 10.65 MHz, and 18.75 MHz in water. For comparison, we also designed planar PMUTs and general curved PMUTs operating around 6 MHz and 15 MHz. Compared to planar PMUTs, curved PMUTs show exceptional performance improvements in output pressure and sensitivity. Moreover, the proposed strategy for bandwidth extension results in 1.33× and 1.25× bandwidth improvements around 6 MHz and 15 MHz. The proposed design methodology is anticipated to assist engineers in designing high-performance PMUT arrays more efficiently and systematically.
Hard sample mining-enabled supervised contrastive feature learning for wind turbine pitch system fault diagnosis
Authors: Wang Zixuan , Ma Ke , Qin Bo , Zhang Jian , Li Mengxuan , Butala Mark D , Peng Peng , Wang Hongwei
Published: July 2024

The presence of multiple failure severities in the wind turbine pitch system due to the long-term wear and tear poses challenges in accurately classifying the system’s health condition, thus increasing maintenance costs or damage risks. This paper proposes a novel method based on hard sample mining (HSM)-enabled supervised contrastive learning to address this problem. The proposed method leverages the powerful feature extraction capabilities of supervised contrastive learning to extract discriminative features from highly imbalanced data. Additionally, the method incorporates a cosine similarity-based HSM framework that constructs hard sample pairs within mini-batches during both the representation learning and classifier training phases, thereby improving the diagnostic performance of the model for hard samples. The proposed method achieves macro G-mean of 0.9991 and 0.9971 on two real datasets containing data on wind turbine pitch system cog belt fractures. These results indicate significantly superior fault diagnosis performance compared to existing methods, highlighting its potential for enhancing the reliability and efficiency of fault diagnosis in wind turbine pitch systems.
A prediction method for the backlash error of robot precision reducers based on optimal assembly
Authors: Li Tianxing , Yao Jian , Xu Jiake , Zhang Yang , Li Tianrui , Li Ziyue , Luo Limin , Gong Linhuan , Nie Shaowu
Published: July 2024

The kinematic accuracy and service life of robot precision reducers are directly affected by their assembly accuracy, and the backlash error is one of the most important performance indicators for evaluating the assembly accuracy. A prediction method for the backlash error of robot precision reducers is proposed, which can quickly and accurately calculate the backlash error of the optimal assembly reducers. Based on the optimal assembly process, the sensitive relationship between the errors of the crucial components and the assembly accuracy of the reducer is analyzed, and the crucial errors affecting the backlash error are identified. The cumulative backlash of the crucial error along the dimensional chain is clarified, and the corresponding relationship between the backlash and the backlash error is determined. On this basis, backlash prediction models are established for the involute planetary gear and cycloidal-pin gear transmission parts, respectively. The mapping relationship between dimensional errors and backlash is also derived. Furthermore, the backlash error of the reducer is obtained by calculating the backlash error caused by each error term of the high-speed stage and low-speed stage transmission parts. Finally, the effectiveness and correctness of the prediction method are verified by the optimal assembly of RV reducers and the measurement of the backlash error. The theory and method proposed in this paper can quickly and accurately predict the backlash error of the reducer for robots, effectively predict the assembly accuracy of the selective reducers, significantly improve the assembly efficiency of the reducers, and then provide theoretical guidance and technical support for enhancing the assembly quality and kinematic accuracy of robot reducers.
Improved assessment of radiofrequency electromagnetic field power deposition near orthopaedic device using a bone-inclusive ASTM phantom under 1.5T and 3T MRI
Authors: Yang Xiaolin , Guo Ran , Zheng Jianfeng , Long Stuart A , Chen Xuemin , Chen Ji
Published: July 2024

Objective. A bone-inclusive ASTM phantom is proposed to improve the assessment of radiofrequency electromagnetic field (RF-EMF) power deposition near orthopedic device under 1.5 T and 3 T magnetic resonance imaging (MRI). Approach. A phantom is created by introducing a cylindrical bone structure inside the American Society for Testing and Materials (ASTM) phantom. Four orthopaedic implant families—rod, nailing system, plate system, and hip replacement—are used in the study. RF-EMF power deposition (in terms of peak averaged specific absorption rate over 1 gram) near these implants are evaluated by placing these implants inside the standard ASTM phantom, the developed bone-inclusive ASTM phantom, and two anatomically representative human body phantoms, known as Duke and Ella. Numerical simulations are performed to calculate the RF-EMF power deposition near various orthopaedic devices within these phantoms. Main Results. For devices implanted inside or near bone tissue, the evaluation of RF-EMF power deposition using the developed bone-inclusive ASTM phantom shows better correlations to the human body phantoms than the ASTM phantom. This improvement is attributed to the portion of the devices implanted within the bone tissue. Significance. The bone-inclusive ASTM phantom has the different tissue of interests surrounding the implants compared to the ASTM phantom. This variation can lead to the different resonance frequency under RF-EMF exposure. This leads to better correlation of RF-EMF power deposition near orthopaedic implants inside human body, making the bone-inclusive ASTM phantom more suitable for evaluating RF-EMF power deposition than ASTM phantom in MRI scans.
Arbitrary low-frequency power-splitting strategy in ferrite/piezoelectric magnetoelectric heterostructures: theory and experimental validation
Authors: Zhang Jitao , Gao Juhang , Filippov Dmitry , Ge Bingfeng , Zhang Qingfang , Poddubnaya Natallia , Zheng Xiaowan , Bian Leixiang , Jiang Liying , Cao Lingzhi
Published: July 2024

Exploring low-frequency (LF) arbitrary power-splitting technologies to address the independent excitation issues of LF/VLF mechanical antennas (MA) with random distributions is challenging due to unidentified device construction and operation mechanism. In light of this, a device construction strategy for three-port magnetoelectric (ME) arbitrary power splitter in composite of ferrite/piezoelectric heterostructure, as well as theoretical model was developed. To validate the feasibility and effectiveness of the strategy, three size-tailored ME samples with length ratio of split PZT segments in 1:1, 2:1, and 3:2 were modeled, fabricated and comparatively characterized. Experimental results show that the achievable maximum power conversion efficiencies (PE) reach 52%, 71%, and 59% for three tailored ME samples, respectively, and as expected the power-splitting ratios are directly proportional to the square ratio of ME voltage coefficient (MEVC) from each port of the tailored ME samples, which are in coincidence with theory under desired operation stability and favorable experiment repeatability evaluated by uncertainties of 0.25854 V cm−1 Oe−1 and 0.32979 V cm−1 Oe−1 for each port. Therefore, a prediction of evolutionary tendency for arbitrary power splitter realization was expanded in view of our experimental observations, and a great flexibility for device future design and further optimization was also provided. Therefore, the presented LF power-splitting strategy paves the ways for arbitrary power splitter realization and enriches the multi-functional ME power electronics families, as well as enables potential applications for efficient excitations of MAs in high-permeable military underwater and civilian emergency rescue distribution long-wave communication system for practical scenarios of submarine, underground railways, tunnels and collapsed residential buildings.
Impact of driver prediction with density deviation and anticipation in lattice hydrodynamic model with passing
Authors: Mehta Shubham , Redhu Poonam
Published: July 2024

This paper presents an integral lattice hydrodynamic model to examine the impact of driver’s anticipation and driving prediction with density deviation of leading vehicle under passing behavior. Both linear and nonlinear investigations have been used to obtain the stability condition and ‘modified Korteweg–de Vries (mKdV)’ equation is derived to further classify the nonlinear behavior of vehicular flow in terms of density waves, respectively. The linear stability condition shows that the stable region can be increased by decreasing the coefficient of predicted density deviation. Additionally, the stable region expands with a positive value of driver anticipation but contracts with a negative value. In comparison of the Nagatani and Redhu models, it is observed that for fixed value of density deviation coefficient, the new model conveys greater stability zone. To verify the theoretical findings, ‘numerical simulation’ has been conducted to examine the evolution of traffic flow in the presence of a small disturbances. The analytical results have been discussed for different passing rate with fixed value of driver’s anticipation and different values of density deviation coefficient. Furthermore, it has been noted that the stable region decreases for all passing rates when driver become more aware of the average speed of any neighbouring vehicles. The obtained results in this paper show that the traffic behavior with the existing model is more realistic. Additionally, this model will help in boosting vehicle movement efficiency, reducing congestion and enhancing road safety effectively .
Three-party semi-quantum secure direct communication based on two communication models
Authors: Tian Yuan , Zhang Nanyijia , Chang Jinyong , Li Jian
Published: July 2024

Based on semi-quantum cryptography and utilizing W-state, this paper introduces two semi-quantum secure direct communication (SQSDC) protocols. SQSDC1 establishes a secret two-way communication channel between a quantum participant and two classical participants. SQSDC2 achieves efficient one-way communication from a quantum user to classical users. Security analysis demonstrates the asymptotic security of the protocols, effectively resisting intercept-measure-resend attacks and entangle-measure attacks from potential eavesdroppers. The efficiency analysis indicates high communication efficiency, with SQSDC1 achieving communication efficiencies of 20%, while SQSDC2 achieves a communication efficiency of 33.33%.
Spinning Proca-Higgs balls, stars and hairy black holes
Authors: Herdeiro Carlos , Radu Eugen , dos Santos Costa Filho Etevaldo
Published: July 2024

Recently, spherical and static flat space solitons (balls) and self-gravitating, everywhere regular, asymptotically flat solitons (stars) were constructed in an Einstein-Proca-Higgs model [1], where a complex vector field gains mass by coupling to a real scalar field with a Higgs-type potential. The Proca-Higgs model serves as a UV completion of a complex Proca model with self-interactions. Here, we construct and examine the mathematical and physical properties of rotating configurations. In particular, rotation allows horizon-bearing solutions, including stationary clouds surrounding Kerr black holes and their non-linear continuation into black holes with Proca-Higgshair.
The hierarchical cosmic web and assembly bias
Authors: Coloma-Nadal J.M. , Kitaura F.-S. , García-Farieta J.E. , Sinigaglia F. , Favole G. , Forero Sánchez D.
Published: July 2024

Accurate modeling of galaxy distributions is paramount for cosmological analysis using galaxy redshift surveys. However, this endeavor is often hindered by the computational complexity of resolving the dark matter halos that host these galaxies. To address this challenge, we propose the development of effective assembly bias models down to small scales, i.e., going beyond the local density dependence capturing non-local cosmic evolution. We introduce a hierarchical cosmic web classification that indirectly captures up to third-order long- and short-range non-local bias terms. This classification system also enables us to maintain positive definite parametric bias expansions. Specifically, we subdivide the traditional cosmic web classification, which is based on the eigenvalues of the tidal field tensor, with an additional classification based on the Hessian matrix of the negative density contrast. We obtain the large-scale dark matter field on a mesh with ~3.9 h
-1 Mpc cell side resolution through Augmented Lagrangian Perturbation Theory. To assess the effectiveness of our model, we conduct tests using a reference halo catalogue extracted from the UNIT project simulation, which was run within a cubical volume of 1 h
-1 Gpc side. The resulting mock halo catalogs, generated through our approach, exhibit a high level of accuracy in terms of the one-, two- and three-point statistics. They reproduce the reference power-spectrum within better than 2 percent accuracy up to wavenumbers k ~ 0.8 h Mpc-1 and provide accurate bispectra within the scales that are crucial for cosmological analysis. This effective bias approach provides a forward model appropriate for field-level cosmological inference and holds significant potential for facilitating cosmological analysis of galaxy redshift surveys, particularly in the context of projects such as DESI, EUCLID, and LSST.
Electron cyclotron current start-up using a retarding electric field in the QUEST spherical tokamak
Authors: Onchi T. , Idei H. , Hanada K. , Watanabe O. , Miyata R. , Zhang Y. , Koide Y. , Otsuka Y. , Yamaguchi T. , Higashijima A. , Nagata T. , Sekiya I. , Shimabukuro S. , Niiya I. , Kono K. , Zennifa F. , Nakamura K. , Ikezoe R. , Hasegawa M. , Kuroda K. , Nagashima Y. , Ido T. , Kariya T. , Ejiri A. , Murakami S. , Fukuyama A. , Kosuga Y.
Published: July 2024

The plasma current start-up experiment is conducted through electron cyclotron (EC) heating in the QUEST spherical tokamak. During the EC heating, the application of a toroidal electric field in the opposite direction to the plasma current effectively inhibits the growth of energetic electrons. Observations show rapid increases in plasma current and hard x-ray count immediately following the cancellation of the retarding electric field. When a compact tokamak configuration maintains equilibrium on the high field side, along with the retarding field, it leads to effective bulk electron heating. This heating achieved an electron temperature of T
e ≈ 1 keV at electron density n
e > 1.0 × 1018 m−3. Ray tracing of the EC wave verifies that more power absorption into plasma through a single-pass occurs around the second resonance layer with higher values of electron density and temperature.
Magnitude-corner frequency distribution of explosion earthquakes: a case study of Anak Krakatau Volcano, Sunda Strait
Authors: Hasib Mohammad , Anwar Arif Nur Bagas , Suhendi Cahli , Kriswati Estu , Anggono Titi , Syuhada  , Febriani Febty , Ramdhan Muhamad , Nirmala Dewi Cinantya , Dwi Prasetio Aditya , Fitro Ghifari Bana , Bagus Adi Prasetyo Hafidz
Published: July 2024

We investigated the distribution between the magnitude and corner frequency of explosion earthquakes at the Anak Krakatau volcano during June - July 2014. We analyzed 100 explosion waveforms recorded at the KRA3 and KRA4 seismic stations located approximately 0.55 km and 3.84 km away from the active crater, respectively. We observed a relationship between the moment magnitude and the corner frequency of the explosion earthquake distribution. The result shows that the moment magnitude is inversely proportional to the corner frequency in a logarithmic scale using the full waveform of explosion earthquakes. The distribution equation of full waveform (0-20s) at KRA3 and KRA4 as follows; fc
= −2.72145 log(Mw
) + 7.99523, and fc
= −1.13971 log(Mw
) + 5.97855 respectively. The magnitude range is approximately 1.5–3 Mw. Meanwhile, the corner frequency range is about 4-8 Hz. Our result shows a similar distribution to those in the tectonic earthquake and volcano studies at different locations which is the magnitude is inversely proportional to the corner frequency. We also observed the relation between seismic moment and corner frequency which shows that the seismic moment is inversely proportional to the corner frequency with the range of seismic moment is about 1013-1015 N.m. Meanwhile, the stress drop is proportional to the corner frequency with the range of stress drop is about 100 and 103 bar. Our results are similar to those of other studies. These parameters show the basic statistical properties of volcanic eruptions. This study is important for understanding the dynamics of volcanic eruptions at the Anak Krakatau volcano.
Identification of geotourism potential for hot spring tourism development in Karangan Sub-District, East Kutai Distric, East Kalimantan Province
Authors: Lismawati E , Sabrian P G , Putri R I , Saepuloh A , Shoedarto R M
Published: July 2024

East Kutai is a district in East Kalimantan Province that possesses a diverse range of stunning geological heritage, distributed throughout the region, each with its own unique allure. In the Karangan District of East Kutai Regency, there are villages that possess alluring geotourism potential in the form of hot springs. Specifically, these hot springs are situated in Batu Lepoq Village and Pangadan Village, and they exhibit promising opportunities for further development. The objective of this research is to assess the state of geotourism in the study region, analyse the appraisal of geotourism potential, and provide recommendations for the development of geology-based tourist in the Karangan sub-district based on the conducted investigation. The study used the geotourism box, Kubalikova quantification analysis (2013), and Geological Survey Centre (2017) as methods. Additionally, interviews are conducted and analysed using SWOT analysis to generate recommendations. According to Kubalikova’s study in 2013, the Batu Lepoq Hot Springs location has a geotourism potential of 58%, indicating a moderate level of geotourism potential. On the other hand, the hot springs and Ampanas Caves have a geotourism potential of 67%, indicating a high level of geotourism potential. These assessments were based on an evaluation of the geological heritage resources [1]. The Batu Lepoq Hot Springs exhibit moderate geotourism potential in terms of scientific value, high geotourism potential in terms of educational value, medium geotourism potential in terms of tourism value, and low geotourism potential in terms of degradation risk. Ampanas Hot Springs exhibits significant geotourism potential due to its scientific and educational value, moderate potential for tourism, and relatively low danger of degradation. Both locations fulfil the requirements for development and management by necessitating increased promotion through various tourism events to attract the community. Additionally, efforts should be made to preserve the natural aesthetics of the surroundings, repair and maintain access roads, install street lights along these roads, and refurbish the pool. Furthermore, it is advisable to construct additional facilities such as toilets, gazebos, and maintenance areas, as well as build new structure.
Identification of geothermal pathways by fault fracture density (ffd) and gravity methods in Karangan sub-district, East Kutai district, East Kalimantan province
Authors: Hutauruk S A Y , Sabrian P G , Putri R I , Saepuloh A , Shoedarto R M
Published: July 2024

The Presence of geothermal manifestations in the form of hot springs is very close to the presence of geological structures that become permeable zones in a Mangkalihat High geothermal system. There are two hot springs in this area, which are crossed by regional structures. So, it is important to identify the geothermal manifestation with the geological structure in this area to know the path of the geothermal flow. In this research, the fault fracture density method is used to determine the existence of structures on surface and the gravity method to determine the existence of structures below surface, which then from the results of the analysis will be correlated with the existence of geothermal manifestations in the area. The analysis results are found with the FFD method. The density of the study area has a value of 0 - 2,355 km/km2. Meanwhile, the results of the gravity method show that there are six normal faults and four thrust faults identified in the study area. Geothermal manifestations in the study area are related to the existence of high-density values in the study area, and geological structures identified through gravity are structures that are the pathway for the movement of hot springs.
Stratigraphy of Salodik Formation in Batutambung section, Toili, Luwuk, Central Sulawesi
Authors: Wijayanti H D K , Husein S
Published: July 2024

Salodik Formation is one of the formations representing a continental drift sequence prior to the collision of Banggai Basin, and it was widely cropped out in the East Arm of Sulawesi. The published geological maps of Luwuk dan Batui describe the Salodik Formation as massive and bedded limestone with marl intercalated and sandstone in the lower part, ranging from Eocene to Late Miocene. In Batutambung, Toili, the geological maps showing the Salodik Formation distributed in a NW-SE trend between two ophiolitic land masses, and suggesting intensive tectonic deformation along the trend. Preliminary geological investigations in this area show that Salodik rock sequences varied from other Salodik outcrops in different areas. Detailed stratigraphic measurements and rock sampling have been carried out along the road connecting Toili and Ampanan Tete., yielding a measured stratigraphy of 70 m vertically thick. Nine lithofacies were identified, i.e., coarse-grained sandstone (cS), micritic sandstone (mcS), fine-medium-grained sandstone (fmS), sandstone with coal spar (SMms), Mudrock (mM), micritic mudrock (mcM), Mudstone (MS), Wackestone (WS) and Packstone (PS). Facies association shows the rock sequence has shallowing upward or prograding pattern with depositional environment varies from an open marine, tidal channel, shoal, and restricted marine/ lagoon Based on foraminifera and nannofossil analysis, Salodik Formation in Batutambung section was deposited in Early Miocene (N6 or NN4-NN6), with paleobathymetry from middle to outer neritic. Based on its age and lithology character, the Salodik Formation in Batutambung is equivalent with Matindok Formation in Tomori PSC.