bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultralow lattice thermal conductivity in type-I Dirac MBene TiB2
Authors: Sharma Ashish , Rangra Vir Singh 
Published: May 2024

Abstract
MBenes, the emergent novel two-dimensional family of transition metal borides have recently attracted remarkable attention. Transport studies of such two-dimensional structures are very rare and are of sparking interest. In this paper Using Boltzmann transport theory with ab-initio inputs from density functional theory, we examined the transport in TiB2 MBene system, which is highly dependent on number of layers. We have shown that the addition of an extra layer (as in bilayer BL) destroys the formation of type-I Dirac state by introducing the positional change and tilt to the Dirac cones, thereby imparting the type-II Weyl metallic character in contrast to Dirac-semimetallic character in monolayer ML. Such non-trivial electronic ordering significantly impacts the transport behavior. We further show that the anisotropic room temperature lattice thermal conductivity κ

L
for ML (BL) is observed to be 0.41 (0.52) and 2.00 (2.04) W m−1 K−1 for x and y directions, respectively, while the high temperature κ

L
(ML 0.13 W m−1 K−1 and BL 0.21 W m−1 K−1 at 900 K in x direction) achieves ultralow values. Our analysis reveals that such values are attributed to enhanced anharmonic phonon scattering, enhanced weighted phase space and co-existence of electronic and phononic Dirac states. We have further calculated the electronic transport coefficients for TiB2 MBene, where the layer dependent competing behavior is observed at lower temperatures. Our results further unravels the layer dependent thermoelectric performance, where ML is shown to have promising room-temperature thermoelectric figure of merit (ZT) as 1.71 compared to 0.38 for BL.
A new method of noise reduction grounded on the Hankel matrix and its application in rubbing fault diagnosis
Authors: Zhang Yi , Yu Mingyue , Feng Zhigang , Ma Ziru 
Published: May 2024

Abstract
In processing signals with singular value decomposition (SVD), one of the keys lies in building an appropriate Hankel matrix from signals. To address the difficulty in extracting the feature information of rubbing faults between rotor and stator, by taking advantage of the nature of rubbing fault information closely related to the rotation period of equipment, a new method of SVD is presented based on the Hankel matrix built from the periodicity of a rotation machine. First, with the periodicity of the rub-impact fault as the basis, the interval step size between Hankel vectors was determined to self-adaptively build a Hankel matrix of signals. Second, the newly-built Hankel matrix was denoised through the singular value differential spectrum. Third, to reduce the loss of data as much as possible, a strategy was proposed to rebuild signals according to the first and last rows of denoised signals. Fourth, features of rubbing faults were extracted according to the frequency spectrum of reconstructed signals, and faults were identified. To verify the applicability and effectiveness of the presented algorithm, various types of simulation signals and tester signals from different states were incorporated. Meanwhile, the presented algorithm was compared with a variety of classical methods. The results prove that the proposed method can not only effectively constrain noise interference, but also highlight fault feature information and correctly identify rub-impact faults.
Micro-scale study of microcapsule cracking performance based on XFEM and fluid cavity model
Authors: Wang Ruotong , Fan Yaqiong , Huang Huiyang , Huang Hua 
Published: May 2024

Abstract
Microcapsule self-healing has become popular for microcrack repairing in resin mineral composites, and the cracking performance of microcapsule directly affect their repair efficiency on the matrix material. In this study, the problem of how the volume of microcapsule core affects the cracking performance of microcapsule is addressed. Based on the extended finite element method, the representative volume element (RVE) considering the volume of microcapsule core is established by combining the cohesive zone model and the fluid cavity model. On this basis, a numerical simulation study of the cracking performance of RVE with different volumes of microcapsule core under dynamic loading is conducted to investigate the triggered cracking process of the fully filled and incompletely filled microcapsules besides their cracking behavior, respectively. This study provides a reference for the preparation of microcapsules and the numerical simulation of microcapsule mechanical properties.
High-quality lateral monolayer-multilayer graphene junction formed by selective laser thinning for self-powered photodetection
Authors: Tang Weijia , Zhu Xiaowen , Huang Jiaxin , Wu Su , Song QiYang , Zhang Butian , Zhang Zemin , Zhang Youwei , Wang Shun 
Published: May 2024

Abstract
The formation of an asymmetric junction is key to graphene-based photodetectors of high-sensitive photodetectability, because such a junction can not only facilitate the diffusion or drift of photogenerated carriers but also realize a self-powered operation. Here, a monolayer-multilayer graphene junction photodetector is accomplished by selectively thinning part of a multilayer graphene to a high-quality monolayer. Benefiting from the large photoabsorption cross section of multilayer graphene and strong asymmetry caused by the significant differences in optoelectronic properties between monolayer and multilayer graphene, the monolayer-multilayer graphene junction shows a 7-fold increase in short-circuit photocurrent as compared with that at the monolayer graphene-metal contact in scanning photocurrent images. The asymmetric configuration also enables the photodetector to work at zero bias with minimized dark current noise and stand-by power consumption. Under global illumination with visible light, a photoswitching ratio of 3.4 × 103, a responsivity of 8.8 mA W−1, a specific detectivity of 1.3 × 108 Jones and a response time of 11 ns can be obtained, suggesting a promising photoresponse. Moreover, it is worth mentioning that such a performance enhancement is achieved without compromising the broadband spectral response of graphene photodetector and it is hence applicable for long wavelength spectral range including infrared and terahertz.
Single-step, in-situ fabrication of flower-like NiCuMn hybrid oxyhydroxide electrodes for enhanced supercapacitor performance
Authors: Kumar Arunesh , Thomas Arpit , Arora Harpreet Singh 
Published: May 2024

Abstract
The rational design of highly active and low-cost electrode material is very promising for energy storage applications. The development of supercapacitors with high energy/power density is an imperative and challenging research objective. Herein, we report a highly facile synthesis approach for developing unique nano-porous hybrid NiCuMn oxyhydroxide architecture with remarkable electrochemical energy storage characteristics. The process involves dealloying of Ni15Cu15Mn70 alloy in an oxygen rich environment, resulting in a uniform 3-dimensional flower like morphology. The dealloyed electrode demonstrates ultra-high specific capacitance of 4110 F cm−3 at a high current density of 20 mA cm−2. A symmetric device exhibits a high volumetric capacitance of 365 F cm−3 at a current density of 10 mA cm−2 with a large potential window of 1.7 V. Even at very high-power density of 850 W l−1, the device exhibits a high energy density of 146 Wh l−1 along with remarkable cyclic stability of 95.4% after 10 000 cycles. The superior performance of nano-porous hybrid NiCuMn oxyhydroxide architecture was attributed to its unique microstructure that provides high surface area, and marginal internal resistance ensuring rapid charge transport.
Optimization of array encoding for ultrasound imaging
Authors: Spainhour Jacob , Smart Korben , Becker Stephen , Bottenus Nick 
Published: May 2024

Abstract

Objective. The transmit encoding model for synthetic aperture imaging is a robust and flexible framework for understanding the effects of acoustic transmission on ultrasound image reconstruction. Our objective is to use machine learning (ML) to construct scanning sequences, parameterized by time delays and apodization weights, that produce high-quality B-mode images. Approach. We use a custom ML model in PyTorch with simulated RF data from Field II to probe the space of possible encoding sequences for those that minimize a loss function that describes image quality. This approach is made computationally feasible by a novel formulation of the derivative for delay-and-sum beamforming. Main results. When trained for a specified experimental setting (imaging domain, hardware restrictions, etc), our ML model produces optimized encoding sequences that, when deployed in the REFoCUS imaging framework, improve a number of standard quality metrics over conventional sequences including resolution, field of view, and contrast. We demonstrate these results experimentally on both wire targets and a tissue-mimicking phantom. Significance. This work demonstrates that the set of commonly used encoding schemes represent only a narrow subset of those available. Additionally, it demonstrates the value for ML tasks in synthetic transmit aperture imaging to consider the beamformer within the model, instead of purely as a post-processing step.
Deciphering oxygen distribution and hypoxia profiles in the tumor microenvironment: a data-driven mechanistic modeling approach
Authors: Kumar P , Lacroix M , Dupré P , Arslan J , Fenou L , Orsetti B , Le Cam L , Racoceanu D , Radulescu O 
Published: May 2024

Abstract

Objective. The distribution of hypoxia within tissues plays a critical role in tumor diagnosis and prognosis. Recognizing the significance of tumor oxygenation and hypoxia gradients, we introduce mathematical frameworks grounded in mechanistic modeling approaches for their quantitative assessment within a tumor microenvironment. By utilizing known blood vasculature, we aim to predict hypoxia levels across different tumor types. Approach. Our approach offers a computational method to measure and predict hypoxia using known blood vasculature. By formulating a reaction-diffusion model for oxygen distribution, we derive the corresponding hypoxia profile. Main results. The framework successfully replicates observed inter- and intra-tumor heterogeneity in experimentally obtained hypoxia profiles across various tumor types (breast, ovarian, pancreatic). Additionally, we propose a data-driven method to deduce partial differential equation models with spatially dependent parameters, which allows us to comprehend the variability of hypoxia profiles within tissues. The versatility of our framework lies in capturing diverse and dynamic behaviors of tumor oxygenation, as well as categorizing states of vascularization based on the dynamics of oxygen molecules, as identified by the model parameters. Significance. The proposed data-informed mechanistic method quantitatively assesses hypoxia in the tumor microenvironment by integrating diverse histopathological data and making predictions across different types of data. The framework provides valuable insights from both modeling and biological perspectives, advancing our comprehension of spatio-temporal dynamics of tumor oxygenation.
A fused LASSO operator for fast 3D magnetic particle imaging reconstruction
Authors: He Jie , Li Yimeng , Zhang Peng , Hui Hui , Tian Jie 
Published: May 2024

Abstract

Objective. Magnetic particle imaging (MPI) is a promising imaging modality that leverages the nonlinear magnetization behavior of superparamagnetic iron oxide nanoparticles to determine their concentration distribution. Previous optimization models with multiple regularization terms have been proposed to achieve high-quality MPI reconstruction, but these models often result in increased computational burden, particularly for dense gridding 3D fields of view. In order to achieve faster reconstruction speeds without compromising reconstruction quality, we have developed a novel fused LASSO operator, total sum-difference (TSD), which effectively captures the sparse and smooth priors of MPI images. Methods. Through an analysis-synthesis equivalence strategy and a constraint smoothing strategy, the TSD regularized model was solved using the fast iterative soft-thresholding algorithm (FISTA). The resulting reconstruction method, TSD-FISTA, boasts low computational complexity and quadratic convergence rate over iterations. Results. Experimental results demonstrated that TSD-FISTA required only 10% and 37% of the time to achieve comparable or superior reconstruction quality compared to commonly used fused LASSO-based alternating direction method of multipliers and Tikhonov-based algebraic reconstruction techniques, respectively. Significance. TSD-FISTA shows promise for enabling real-time 3D MPI reconstruction at high frame rates for large fields of view.
Towards precise LET measurements based on energy deposition of therapeutic ions in Timepix3 detectors
Authors: Félix-Bautista Renato , Hamad Yasmin , Yáñez-González Tomás , Ochoa-Parra Pamela , Granja Carlos , Martišíková Mária , Mairani Andrea , Gehrke Tim 
Published: May 2024

Abstract

Objective. There is an increasing interest in calculating and measuring linear energy transfer (LET) spectra in particle therapy in order to assess their impact in biological terms. As such, the accuracy of the particle fluence energy spectra becomes paramount. This study focuses on quantifying energy depositions of distinct proton, helium, carbon, and oxygen ion beams using a silicon pixel detector developed at CERN to determine LET spectra in silicon. Approach. While detection systems have been investigated in this pursuit, the scarcity of detectors capable of providing per-ion data with high spatial and temporal resolution remains an issue. This gap is where silicon pixel detector technology steps in, enabling online tracking of single-ion energy deposition. The used detector consisted of a 300 µm thick silicon sensor operated in partial depletion. Main results. During post-processing, artifacts in the acquired signals were identified and methods for their corrections were developed. Subsequently, a correlation between measured and Monte Carlo-based simulated energy deposition distributions was performed, relying on a two-step recalibration approach based on linear and saturating exponential models. Despite the observed saturation effects, deviations were confined below 7% across the entire investigated range of track-averaged LET values in silicon from 0.77 keV µm−1 to 93.16 keV µm−1. Significance. Simulated and measured mean energy depositions were found to be aligned within 7%, after applying artifact corrections. This extends the range of accessible LET spectra in silicon to clinically relevant values and validates the accuracy and reliability of the measurements. These findings pave the way towards LET-based dosimetry through an approach to translate these measurements to LET spectra in water. This will be addressed in a future study, extending functionality of treatment planning systems into clinical routine, with the potential of providing ion-beam therapy of utmost precision to cancer patients.
Development of an inertia-driven resonant piezoelectric stack pump based on the flexible support structure
Authors: Chen Jian , Jin Rong , Gao Wenzhi , Liu Changhai , Zeng Yishan , Wang Jingwu 
Published: May 2024

Abstract
This paper proposes an inertia-driven resonant piezoelectric stack pump based on a flexible support structure to solve the problem that the piezoelectric stack cannot effectively drive the diaphragm pump to transport liquid due to too small output displacement and too high resonant frequency when one end is fixed. Under the inertial force generated by the vibration of the piezoelectric stack’s mass center during its deformation, the whole piezoelectric stack will vibrate with the flexible support structure; and a large displacement and inertial force can be achieved to drive the pump at the resonant frequency. Piezoelectric pumps are designed with a diaphragm pump and a piezoelectric stack based on the flexible support structure. The piezoelectric vibrator includes a piezoelectric stack, a preloading component and a flexible support plate. A fixed support plate and three flexible support plates with different stiffnesses were fabricated and assembled with the same piezoelectric stack and diaphragm pump respectively to construct four piezoelectric pump prototypes with different resonant frequencies. The temperature rise characteristics of the piezoelectric stack were experimentally studied to determine the safe range of the driving voltage and frequency. Then the output performances of the piezoelectric pumps were tested. Under a sinusoidal driving voltage of 100 Vpp, the piezoelectric pump based on the fixed support structure cannot pump water, while the piezoelectric pumps based on the flexible support structure achieved the maximum flow rates of 89.0 ml min−1, 123.4 ml min−1 and 197.4 ml min−1 at the resonant frequencies of 262 Hz, 297 Hz and 354 Hz, and the maximum backpressures of 4.4 kPa, 7.5 kPa and 11.0 kPa at 266 Hz, 309 Hz and 365 Hz.
Electrical/thermal triggering on shape memory composite tubes with different braiding angles
Authors: Yang Qin , Liu Renyi , Gu Bohong , Sun Baozhong , Han Chaofeng , Zhang Wei 
Published: May 2024

Abstract
2D braided shape memory composite (SMPC) tubes, with near-net shape manufacturing and programmable, are widely utilized in smart structures. Here we have developed braided tubes of continuous carbon fiber reinforced shape memory polyurethane (SMPU) composites. This innovative design yields a synergistic boost in both mechanical strength, shape memory functionality, and dual-trigger responsiveness. The mechanical properties, electrical/thermal shape memory performance, and recovery force of the SMPC tubes with various braiding angles have been investigated. The effects of braiding angle, temperature dependence, and applied current on the mechanical properties and shape memory properties were revealed. We found a substantial increase in compression load and ring stiffness as the braiding angle increased and the temperature decreased. The SMPC tubes exhibited a recovery ratio of 99% under electrical and thermal triggering, demonstrating a more rapid shape recovery compared to the SMPU tubes solely under thermal triggering. The large-angle specimens exhibited shorter recovery times, higher recovery forces (up to 11.40 N), and faster responses upon electrical stimulation. The ability of SMPC tubes to generate a recovery force several times greater than their weight holds great potential for expanding the applications of smart actuators.
Characterization of titanium dioxide nanomaterials synthesized from leaf extract of Pogostemon cablin Benth and their potential antifungal activity
Authors: Shukla Mohee , Narain Satya , Kumar Ashwani , Dikshit Anupam 
Published: May 2024

Abstract
Recently, dermal infections caused by fungus have increased drastically, affecting people’s daily lives and causing embarrassment. These infections are either due to dermatophytes or non-dermatophytic fungi. Basically, three genera of dermatophytes namely Trichophyton, Microsporum and Epidermohyton are the main cause of dermatophytosis. Candida albicans is also responsible for some dermal infections as a non-dermatophytic fungus. Traditional antifungal compounds cause side effects and resistance in fungi, so better and non-toxic alternatives are needed. Now a day’s, nanotechnology is widely used in the pharmaceutical field and has proven to be a good antifungal agent. This study used TiO2 nanoparticles (NPs) against four human pathogens Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum gypseum, and Candida albicans. Green and chemical synthesis methods were used for the synthesis of TiO2 nanoparticles. In green synthesis, we used aqueous leaf extract of Pogostemon cablin Benth. The formation of TiO2 nanoparticles is confirmed by UV-visible spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) analysis. According to XRD, the average size of chemically synthesized nanoparticles was 70.52 nm, while green synthesized nanoparticles were 71.82 nm. All the characterizations support that Pogostemon cablin aqueous extract can synthesize TiO2 nanoparticles. The minimum inhibitory concentration was determined according to the broth microdilution recommended assay. This study concluded that green synthesized TiO2 NPs showed good results against all four pathogens.
Transient behaviour analysis in silicon carbide alpha particle detector using TCAD and SRIM simulation
Authors: He Xiaoying , Cao Pengcheng , Lu Zhangyu , Rao Lan , Xin Xiangjun 
Published: May 2024

Abstract
Time response characteristics of α particle detector are crucial for monitoring radiation fields varied with time and its characterization of pulse radiation field. Here, SRIM-informed TCAD simulation is utilized to visually investigate the transient behaviors of carriers and alpha particles in 4H-SiC Schottky barrier detectors for the time response characteristics. We identified external bias voltage and incident particle energy as key factors to influence transient current pulse broadening. Low-energy alpha particles result in low initial kinetic energy of the ionization-generated carriers, leading to transient current broadening and reduced time resolution characteristics. Conversely, high-energy alpha particles ionize carrier with high drift velocity, preventing the broadening effect. Our simulation provides a planform and valuable guidance for optimizing alpha particle detector, selecting appropriate bias voltages, and enhancing time resolution capabilities.
Core-shell NiS-poly-2-aminothiophenol/NiO nanocomposite of ring-shape for supercapacitor applications
Authors: Rabia Mohamed , Esayed Asma M , Alkallas Fatemah H , Ben Gouider Trabelsi Amira 
Published: May 2024

Abstract
A novel ring-shaped NiS-poly-2-aminothiophenol NiO (NiS-P2ATP/NiO) core–shell nanocomposite has been successfully synthesized and extensively analyzed, presenting itself as a promising material for a two-electrode configuration pseudo-supercapacitor, tested in both basic and acidic mediums. The SEM analysis reveals the construction of open-ring shapes, characterized by a wall thickness of approximately 120 nm and a height of around 100 nm. To confirm the elements and crystallinity behavior of this nanocomposite, XPS and XRD analyses are used, while FTIR is performed to confirm the functional groups. The electrical properties of this nanocomposite were thoroughly investigated through various techniques, including charge/discharge, cyclic voltammetry, and EIS. The efficiency of the fabricated supercapacitor was assessed through measured specific capacitance (CS), energy density (E), power density (P), Ragone plot, and the values of RS and RCT resistances. The specific capacitance value is significantly higher at 59.8 F g−1 compared to the basic medium’s CS value of 30 F g−1. In the acidic medium, the E values reached 5.0 W h kg−1, while in the basic electrolyte, it amounted to 2.5 W h kg−1. The produced P achieved impressive values, reaching 28800 and 28700 W kg−1 at 0.2 A g−1 in the acidic and basic mediums, correspondingly. The unique behavior of this novel composite suggests its potential for industrial applications of polymer materials, given its ease of preparation, mass production feasibility, and cost-effectiveness. The findings of this study open doors for the practical implementation of such innovative materials in energy storage technologies.