bluuebunny/crossref_metadata_2025 huggingface dataset:
CD133-targeted multifunctional nanomicelles for dual-modality imaging and synergistic high-intensity focus ultrasound (HIFU) ablation on pancreatic cancer in nude mice
Authors: Yao Yijing , Zheng Yiwen , Wu Mingtai , Gao Yihui , Yu Qian , Liu Mengyao , Luo Xiaoxiao , Wang Rui , Jiang Lixin
Published: May 2024

Targeted multifunctional nanomicelle synergy with high-intensity focused ultrasound improves pancreatic cancer treatment efficacy.
Alternately electrodeposited mesoporous NiCoSe2@MnO2 nanocomposite-anchored Ni–Co layered double hydroxide nanoneedles for hybrid supercapacitors
Authors: Wang Fangqiao , Zhao Zhibo , Fu Xiaoguang , Li Baobao , Chen Zhuomin , Wang Senjing , Huang Qiaoling , Xu Qingchi , Ye Meidan
Published: May 2024

A rational strategy was designed to hydrothermally grow NiCo-layered double hydroxide nanoneedles with alternately electrodeposited NiCoSe2 and MnO2 on carbon fibers with enhanced electrochemical performance and cycling stability.
Exploring Health-Related Social Needs and Components of Social Competence Following Childhood Traumatic Brain Injury
Authors: Dart Libby , Ciccia Angela
Published: May 2024

Purpose:

Health-related social needs (HRSNs) impact general health care and educational outcomes for children with traumatic brain injury (TBI) and their families. Furthermore, children with TBI of all severities experience negative social competence outcomes chronically postinjury. However, studies have not investigated the relationship between HRSNs and social competence outcomes for children after TBI. The aim of this study was to identify the relationship between HRSNs and components of social competence (i.e., social skills, social communication, family functioning, and behavioral domains per the biopsychosocial framework for social competence) for children with TBI, per parent report.

Method:

This study used a prospective, cross-sectional study design with a convenience sample. Online surveys were completed by parents of children with TBI (
N
= 22). On average, children with TBI were 4.84 years old at the time of their TBI and 9.24 years old at the time of study participation.

Results:

Having a parent identify an HRSN in the domain of mental health was associated with social communication and family functioning difficulties for children with TBI. Statistically significant relationships were found between social communication and family functioning, externalizing behavior, and total behavior; family functioning and social relations; and family functioning and externalizing behavior.

Conclusions:

The findings of this study support that children with TBI experience chronic deficits in components of social competence, and HRSNs are associated with these outcomes. Further research needs to consider HRSNs to improve equitable prevention, supports, and services for children with TBI.
Residual multimodal Transformer for expression‐EEG fusion continuous emotion recognition
Authors: Jin Xiaofang , Xiao Jieyu , Jin Libiao , Zhang Xinruo
Published: May 2024

Continuous emotion recognition is to predict emotion states through affective information and more focus on the continuous variation of emotion. Fusion of electroencephalography (EEG) and facial expressions videos has been used in this field, while there are with some limitations in current researches, such as hand‐engineered features, simple approaches to integration. Hence, a new continuous emotion recognition model is proposed based on the fusion of EEG and facial expressions videos named residual multimodal Transformer (RMMT). Firstly, the Resnet50 and temporal convolutional network (TCN) are utilised to extract spatiotemporal features from videos, and the TCN is also applied to process the computed EEG frequency power to acquire spatiotemporal features of EEG. Then, a multimodal Transformer is used to fuse the spatiotemporal features from the two modalities. Furthermore, a residual connection is introduced to fuse shallow features with deep features which is verified to be effective for continuous emotion recognition through experiments. Inspired by knowledge distillation, the authors incorporate feature‐level loss into the loss function to further enhance the network performance. Experimental results show that the RMMT reaches a superior performance over other methods for the MAHNOB‐HCI dataset. Ablation studies on the residual connection and loss function in the RMMT demonstrate that both of them is functional.
Join multiple Riemannian manifold representation and multi‐kernel non‐redundancy for image clustering
Authors: Zhang Mengyuan , Liu Jinglei
Published: May 2024

Image clustering has received significant attention due to the growing importance of image recognition. Researchers have explored Riemannian manifold clustering, which is capable of capturing the non‐linear shapes found in real‐world datasets. However, the complexity of image data poses substantial challenges for modelling and feature extraction. Traditional methods such as covariance matrices and linear subspace have shown promise in image modelling, and they are still in their early stages and suffer from certain limitations. However, these include the uncertainty of representing data using only one Riemannian manifold, limited feature extraction capacity of single kernel functions, and resulting incomplete data representation and redundancy. To overcome these limitations, the authors propose a novel approach called join multiple Riemannian manifold representation and multi‐kernel non‐redundancy for image clustering (MRMNR‐MKC). It combines covariance matrices with linear subspace to represent data and applies multiple kernel functions to map the non‐linear structural data into a reproducing kernel Hilbert space, enabling linear model analysis for image clustering. Additionally, the authors use matrix‐induced regularisation to improve the clustering kernel selection process by reducing redundancy and assigning lower weights to identical kernels. Finally, the authors also conducted numerous experiments to evaluate the performance of our approach, confirming its superiority to state‐of‐the‐art methods on three benchmark datasets.
Object recognition based on shape interest points descriptor
Authors: Zhang Lei , Pu Jiexin
Published: May 2024

Considering the defect of object recognition with single global feature or local feature, in this letter the authors propose a shape interest points descriptor (SIPD) for object recognition. Particularly, the authors extract the shape features by the improved HU moments and then interest points by Speeded up Robust Feature (SURF). Object recognition is carried out by similarity measure. Because the influence of the improved HU moments and SURF for object recognition is different, the two different similarity measures are fused effectively by using different weight factors. Experimental results show that the author’ proposed method is effective and robust to the changes of scale, viewing angle, illumination and noise when compared with the other representative methods.
Transient overvoltage suppression of LCC‐HVDC sending‐end system based on DC current control optimisation
Authors: Wang Yang , Zhu Jianhang , Li Yingbiao , Hu Jiabing , Ma Shicong , Wang Tiezhu
Published: May 2024

The receiving‐end system AC fault of the line‐commutated‐converter‐based high voltage direct current (LCC‐HVDC) will lead to commutation failure of the inverter side. During the fault and its recovery, AC transient low voltage and transient overvoltage (TOV) will occur in the sending‐end system. The TOV has the risk of triggering the disorderly off‐grid of the nearby renewable power generations. Besides, in a serious situation, it will threaten the power system to maintain a secure and steady operation. Therefore, the authors analyse the mechanism involved in the AC transient voltage during the AC fault and the recovery period first. It reveals that the key factor causing the TOV of the sending‐end system is the setting of the DC current reference value. Then, a DC current reference value limit method based on the AC TOV sampling value is proposed, which is used to accelerate DC current recovery and suppress the TOV of the sending‐end system. Finally, the effectiveness of the designed control method has been confirmed through electromagnetic transient simulations using the CIGRE HVDC benchmark model and a ±800 kV HVDC transmission system model situated in Northwest China.
Chromatic Light Therapy for Inhibiting Myopia Progression: Human Studies
Authors: Swiatczak Barbara
Published: May 2024

Myopia, a common refractive error, has been associated with various risk factors, but time outdoors has emerged as a significant protective factor against its onset. This association is believed to be mediated by the influence of sunlight on dopamine release, a neurotransmitter crucial for regulating eye growth. Recent research has explored the specific properties of light in order to identify potential interventions for myopia control in children. Low-level red light therapy has gained attention, and has shown promise in inhibiting myopia progression, although there are concerns about safety and rebound effects. Similarly, blue light stimulation aims to upregulate retinal dopamine activity, yet conclusive evidence supporting its efficacy is lacking. Moreover, researchers explored the use of the entire visible light spectrum by digitally imposing longitudinal chromatic aberration to adjust proper eye growth. Preliminary findings suggest that digitally simulated chromatic
aberration could potentially serve as a myopia control strategy and highlights the need for further investigation into long-term effects. As research progresses, understanding the efficacy and safety of light-based interventions for myopia control remains crucial for informing clinical practice and optimizing patient outcomes.
Antenatal Breast Milk Expression Survey of Individuals Whose Pregnancy Was Complicated by Diabetes: Exploring Knowledge, Perceptions, Experiences, and Milk Volume Expressed
Authors: Mess Sarah , Palatnik Anna , Cabacungan Erwin
Published: May 2024

Objective Antenatal breast milk expression (ABE) offers a host of benefits, including reduced formula consumption, support for breastfeeding success, and increased maternal satisfaction. Despite these advantages, experience with ABE differs significantly, often leading to anxiety over perceived inadequate milk supply and eventual breastfeeding cessation. This study comprehensively evaluates the knowledge, attitudes, and real-world experiences of individuals with gestational or pregestational diabetes concerning ABE, with a focus on total milk volume expressed prior to birth.

Study Design Utilizing a convenience sampling method, we surveyed individuals with gestational or pregestational diabetes from three health care facilities who were trained in ABE. Knowledge and perceptions were gauged through presurvey statements, while postsurvey statements were employed to measure experiences, both using a 5-point Likert scale. In parallel, a retrospective study assessed both maternal and infant outcomes among the same participant pool. Statistical comparisons between individuals with and without reservations were made using the Wilcoxon signed rank sum, Mann–Whitney, chi-square, and Fisher's exact tests.

Results Of the 138 participants, 75% completed both survey segments, and 61% expressed reservations about ABE. Both groups were demographically similar and showed comparable newborn outcomes. However, individuals with reservations experienced heightened pain during ABE, reported lesser lactation support, and were less willing to repeat the process compared to those individuals without reservations. The median total ABE volume was significantly lower by 14 mL among those with reservations (7 vs. 21 mL, p = 0.009). Although both groups demonstrated improved attitudes toward the utility of ABE for individuals with gestational or pregestational diabetes, no significant shift occurred in the perception of ABE difficulty.

Conclusion Our results indicate that individuals with gestational or pregestational diabetes who have reservations about ABE face unique challenges and tend to express lower milk volumes. This underlines the need for specialized interventions and ongoing research to address antenatal lactation support and alleviate ABE-related concerns among individuals with gestational or pregestational diabetes.

Key Points
Bosonic rational conformal field theories in small genera, chiral fermionization, and symmetry/subalgebra duality
Authors: Rayhaun Brandon C.
Published: May 2024

A (1 + 1)D unitary bosonic rational conformal field theory (RCFT) may be organized according to its genus, a tuple (c,C) consisting of its central charge c and a unitary modular tensor category C which describes the (2 + 1)D topological quantum field theory for which its maximally extended chiral algebra forms a holomorphic boundary condition. We establish a number of results pertaining to RCFTs in “small” genera, by which we informally mean genera with the central charge c and the number of primary operators rank(C) both not too large. We start by completely solving the modular bootstrap problem for theories with at most four primary operators. In particular, we characterize, and provide an algorithm which efficiently computes, the function spaces to which the partition function of any bosonic RCFT with rank(C)≤4 must belong. Using this result, and leveraging relationships between RCFTs and holomorphic vertex operator algebras which come from “gluing” and cosets, we rigorously enumerate all bosonic theories in 95 of the 105 genera (c,C) with c ≤ 24 and rank(C)≤4. This includes as (new) special cases the classification of chiral algebras with three primaries and c < 120/7 ∼ 17.14, and the classification of chiral algebras with four primaries and c < 62/3 ∼ 20.67. We then study two applications of our classification. First, by making use of chiral versions of bosonization and fermionization, we obtain the complete list of purely left-moving fermionic RCFTs with c < 23 as a corollary of the results of the previous paragraph. Second, using a (conjectural) concept which we call “symmetry/subalgebra duality,” we precisely relate our bosonic classification to the problem of determining certain generalized global symmetries of holomorphic vertex operator algebras.
Direct measurement of repulsive and attractive pair potentials using pairs of optical traps
Authors: Bell-Davies Miranda C. R. , Codina Joan , Curran Arran , Dobnikar Jure , Dullens Roel P. A. , Pagonabarraga Ignacio
Published: May 2024

We present a technique for measuring the interactions between pairs of colloidal particles in two optical traps. This method is particularly suitable for measuring strongly attractive potentials, an otherwise challenging task. The interaction energy is calculated from the distribution of inter-particle separations by accounting for the contribution from the optical traps with arbitrary trap profiles. The method is simple to implement and applicable to different types of pair potentials and optical trapping geometries. We apply the method to measure dipolar pair interactions in experiments with paramagnetic colloids in external magnetic fields. We obtain consistent and accurate results in all regimes, from strongly attractive to repulsive potentials. By means of computer simulations, we demonstrate that the proposed method can be successfully applied to systems with complex pair interactions characterized by multiple attractive and repulsive regimes, which are ubiquitous in soft and biological matter.
Finite-displacement elastic solution due to a triple contact line
Authors: Olives Juan
Published: May 2024

At the line of triple contact of an elastic body with two immiscible fluids, the body is subjected to a force concentrated on this line, the fluid–fluid surface tension. In the simple case of a semi-infinite body, limited by a plane, a straight contact line on this plane, and a fluid–fluid surface tension normal to the plane, the classical elastic solution leads to an infinite displacement at the contact line and an infinite elastic energy. By taking into account the body–fluid surface tension (i.e., isotropic surface stress) and applying Kolosov’s approach of plane strain elasticity, we present a new and simple expression of the solution concerning the semi-infinite body, which gives a finite displacement and a ridge at the contact line, and finite elastic energy. A detailed description of the displacements, strains, and stresses in the neighborhood of the contact line is given. This solution also shows that Green’s formulae, in the volume and on the surfaces, are valid (these formulae play a central role in the theory).
Non-destructive characterization of silicon nanowires and nanowire coatings using mid-infrared spectroscopy
Authors: Esfidani S. Maryam Vaghefi , Keefe Daniel W. , Toor Fatima , Folland Thomas G.
Published: May 2024

Silicon nanowires (SiNWs) have attracted much attention owing to their potential applications in electronics and photonics, while remaining as a cost-effective material platform. Key material properties in engineering SiNWs for different applications include their length, density, and presence of oxides or other chemicals on the surface. However, monitoring these properties is challenging, as scanning electron microscopy and atomic force microscopy (AFM), which directly image the wires, require destructive cleaving of the sample. This paper uses polarized, variable-angle Fourier Transform IR reflectance spectroscopy as a nondestructive technique to characterize the areal density and length of metal-assisted chemically etched SiNW arrays. In addition to the ability to characterize “as-etched” wires, we show that IR spectroscopy can also measure few-nanometer thick layers of aluminum oxide (AlOx) grown radially around the length of the SiNWs utilizing atomic layer deposition. Despite sample inhomogeneities, an effective medium theory (EMT) model can determine the length and density of the NWs for a range of lengths between 3 and 14 μm. The EMT can also reproduce the experimentally measured vibrational bands for coated NWs, demonstrating that IR spectroscopy can also evaluate the presence of molecular contaminants on the wires.
Innovative pre-fire alert smart detection system-based embedded system
Authors: Al-Chalabi Sadeem Marouf , Al-Chalabi Atheer Marouf , Al-Khafaji Rami Ali
Published: May 2024

Early fire identification is critical to saving lives and property. One viable strategy for improving fire detection systems’ efficacy and precision is the use of Internet of Things (IoT) technology. This article details research into the conception and development of an IoT, ESP32-based, Arduino MEGA-connected smart pre-alert detection system for fires. Because of its flexible nature, the Arduino microcontroller can easily exchange data with various sensors for real-time monitoring and analysis. This study surveys the existing literature to provide insight into many approaches to early fire detection (forecasting), such as sensor fusion methods and the use of the intelligence concept as a pre-predictor. The research highlights the need to set up sophisticated fire monitoring and alarm systems and to develop predictive models based on sensor data. This study illustrates how embedded systems via IoT technology and the ESP32 architecture may improve the efficiency and dependability of very early fire detection systems. This research adds to the expanding corpus of information that may be used to improve fire safety in contemporary settings. The proposal’s sensors include an Arduino MEGA, an ESP32, a MAX6675 module, an MQ-Smoke, and an MQ-Natural Gas for collecting data, which are then processed using Cloud Firebase and a sleek mobile interface that can be reached overseas at any time.
Finite pedestal width formation from early L-H transition stage with a strong edge safety-factor dependence through the resistive ballooning mode
Authors: Kim J. Y. , Han H. S.
Published: May 2024

An approximate modeling of the low- to high-confinement (L-H) transition dynamics is given using the method, similar to that by Hinton et al. [Phys. Fluid B 5, 1281 (1993)], but considering more explicitly the L-mode edge turbulence which is here assumed to be dominated by the resistive ballooning mode (RBM) near the separatrix, while the ion temperature gradient (ITG) mode in the inner edge–core region. It is shown that the L-H transition can then be initiated from an inner edge near the ITG-RBM transition point with a finite width. Especially, this width is found to have a strong edge safety-factor or poloidal field dependence, similar to that shown by the EPED1 model. Meanwhile, unlike the pedestal width, the H-mode threshold power appears to be much less sensitive to the edge safety-factor, in qualitative agreement with the observed weak dependence of the threshold power on plasma current (IP). From an additional brief check, these dependences on IP are also found to be quite different from the behavior of other parameters (ion mass, toroidal field, plasma density, and effective Z-number) where the threshold power depends relatively strongly while the initial width depends somewhat weakly on most of them, except the effective Z-number.
Thermal transport of confined water molecules in quasi-one-dimensional nanotubes
Authors: Imamura Shun , Kobayashi Yusei , Yamamoto Eiji
Published: May 2024

Dimensions and molecular structures play pivotal roles in the principle of heat conduction. The dimensional characteristics of a solution within nanoscale systems depend on the degrees of confinement. However, the influence of such variations on heat transfer remains inadequately understood. Here, we perform quasi-one-dimensional non-equilibrium molecular dynamics simulations to calculate the thermal conductivity of water molecules confined in carbon nanotubes. The structure of water molecules is determined depending on the nanotube radius, forming a single-file, a single-layer, and a double-layer structure, corresponding to an increasing radius order. We reveal that the thermal conductivity of liquid water has a sublinear dependency on nanotube length exclusively when water molecules form a single file. A stronger confinement leads to behavioral and structural characteristics closely resembling a one-dimensional nature. Moreover, single-layer-structured water molecules exhibit enhanced thermal conductivity. We elucidate that this is due to the increase in the local water density and the absence of transitions to another layer, which typically occurs in systems with double-layer water structures within relatively large radius nanotubes.
A novel nanoplasmonic-based diagnosis platform: Advances and emerging technologies
Authors: Kim Gyeong-Ji , Seo Sung Eun , Kim Seo Jin , Lee Kyoung G. , Kwon Oh Seok
Published: May 2024

The development of a rapid, simple, inexpensive, and sensitive nucleic acid assay is critical in ultrafast diagnostic systems to prevent the rapid spread of novel infectious agents. However, current representative diagnostic methods, such as the polymerase chain reaction (PCR), are bulky, expensive, complex, and time-consuming. The plasmonic photothermal effect of plasmonic materials is widely used in biological applications because of excellent properties, such as strong optical properties and enhanced local electromagnetic field. PCR methods using plasmonic nanostructures are used to overcome the limitations of conventional PCR. Therefore, plasmonic photothermal-based PCR exhibit a rapid ramping rate, ultrafast amplification, high sensitivity, cost-effectiveness, and compactness, which can be used as a point-of-care device in situ. This study reviewed the mechanisms of plasmonic PCR and various materials, such as organic, inorganic, and hybrid materials, used in PCR. Furthermore, the properties, light source, amplification efficiency, and monitoring method of classified plasmonic materials were compared. This review introduced the disease diagnosis application using plasmonic PCR and evaluated the prospect of potential future applications as next-generation PCR.
Distinct differences in surface transport between electrolyte-gated (110) and (001) SrTiO3
Authors: Chen P. Z. , Zhang J. H. , Zhou G. Z. , Zhai W. J. , Lin L. , Yan Z. B. , Chen C. , Jiang X. P. , Lu C. L. , Liu J.-M.
Published: May 2024

Electrolyte gating technology has been widely used as an effective tool to study novel physics at complex oxide surfaces and interfaces. Certain emergent phenomena reported in electro-gated SrTiO3 (STO) surfaces are particularly interesting. Here, we report on the disparate electron transport behaviors of electrolyte-gated STO (001) and (110) oriented surfaces. In contrast to the anomalous transport from an insulating state to a Kondo-like state and then metallic states on the (001) surface, with increasing carrier density, the (110) surface always behaves as an insulating state. A comparison study suggests that the oxygen vacancies and localized Ti3+ ions on the (001) surface are scatter carriers, but no such defects are found on the (110) surface. This suggests that these surfaces are intrinsically insulating, and the observed anomalous effects are likely induced by the Ti3+ ions and oxygen vacancies introduced during electrolyte gating. This work sheds light on complicated phenomena in electrolyte-gated STO-based systems.
On-state electrical stress-induced degradation of NiO/β-Ga2O3 heterojunction pn diodes
Authors: Wang Yingzhe , Zheng Xuefeng , Zhu Jiaduo , Pan Ailing , Bu Sijie , Hong Yuehua , Zhang Jincheng , Guo Lixin , Ma Xiaohua , Hao Yue
Published: May 2024

Degradation and trap evolution in NiO/β-Ga2O3 heterojunction pn diodes under on-state electrical stress were investigated in this work using deep-level transient spectroscopy measurements and density functional theory (DFT) calculations. The decrease in turn-on voltage and forward current appears to correlate with an increase in the concentration of the compensating acceptor-like traps. From the energy level of EV + 1.3 eV, the corresponding acceptor-like traps can be attributed to the Ga vacancy complex with hydrogen (VGa-H). Interestingly, accompanied by the increase in VGa-H concentration, the self-trapped holes (STH) originally passivated by H may gradually recover. DFT calculations show a monotonous decrease in energy, suggesting the spontaneous diffusion of hydrogen from STH passivated sites to the adjacent VGa, which are generated under stress. This phenomenon leads to the recovery of STH and the generation of VGa-H. This investigation offers new insights into the degradation mechanisms of β-Ga2O3-based devices under electrical stress.
A gradient aerodynamic optimization method based on deep learning
Authors: Wu Hao , Chen Rongqian , Lou Jinhua , You Yancheng , Huang Longtai , Xu Mingxuan , Ruan Yuan
Published: May 2024

Gradient-based aerodynamic optimization methods involve complex gradient calculations with high computational costs. To address these problems, this paper proposes a rapid deep learning-based method for predicting the aerodynamic force gradients and establishes an aerodynamic optimization framework. A deep neural network is used to determine the latent mapping relationship between the near-wall flow field information and the aerodynamic force gradients, and the resulting gradient prediction model is integrated into an aerodynamic optimization platform. Combining grid deformation techniques with gradient-based optimization enables the aerodynamic optimization of airfoils. The deep neural network model can rapidly predict gradients that are basically consistent with those from the traditional discrete adjoint method, and decouples the gradient computation from the flow field solution process. The proposed method is validated through the aerodynamic optimization of the airfoil. Under various optimization objectives and initial conditions, the deep neural network model significantly improves the aerodynamic performance of the airfoil and substantially enhances the efficiency of optimization compared with traditional methods.
Electrically active defects induced by thermal oxidation and post-oxidation annealing of n-type 4H-SiC
Authors: Kumar P. , Bathen M. E. , Martins M. I. M. , Prokscha T. , Grossner U.
Published: May 2024

In this work, we have performed a detailed study of the defects created in the bulk of 4H-SiC after thermal oxidation and post oxidation annealing using deep level transient spectroscopy and minority carrier transient spectroscopy (MCTS). The study reveals the formation of several shallow and deep level majority carrier traps in the bandgap. The ON1 (EC−0.85 eV), ON2a (EC−1.05 eV), and ON2b (Ec−1.17 eV) levels are the most dominant and are observed across all the samples (EC denotes the conduction band edge). Three shallow levels Ti(k) (EC−0.17 eV), E0.23 (EC−0.23 eV), and C1/2 (EC−0.36/0.39 eV) are observed in the samples. For most of the majority carrier defects, the highest concentration is observed after an NO anneal at 1300°C. This behavior is sustained in the depth profile measurements where the defect concentration after the NO anneal at 1300°C is significantly higher than for the rest of the samples. The origin of most of the majority carrier defects has been attributed to C interstitial injection from the interface during thermal oxidation and annealing. MCTS measurements reveal two prominent minority carrier traps, labeled O0.17 (EV+0.17 eV) and B (EV+0.28 eV), where the concentration of O0.17 is independent of annealing parameters while the concentration of the B level increases after the NO anneal (EV denotes the valence band edge). Furthermore, the depth profiles of the defects are used to evaluate their diffusion parameters by solving the diffusion equation to fit the experimental profiles. The defect concentrations decay exponentially with depth, which evidences that the defects were created at or near the SiO2–SiC interface and migrate toward the bulk during oxidation and post-oxidation annealing.
Green synthesis and characterization of gold nanoparticles from discarded computer PCBs on reduction of environmental pollution
Authors: Mondal Pronoy , Haque Mohammad Salman , Ghose Biswajit , Afridi Ahsan Ahammed
Published: May 2024

The economic value of gold content in electronic waste, particularly waste printed circuit boards (PCBs), has generated interest in recovering gold from this material. Unfortunately, due to the severe environmental hazards associated with such waste, there is a pressing need for efficient and selective methods of gold nanoparticle recovery. A novel technique has been developed to synthesize gold nanoparticles that employ chlorate leaching and Punica granatum extract to minimize the environmental impact of electronic waste. Multiple analytical methods, including UV-Vis, XRD, EDS, SEM, and TEM analysis, were utilized to identify and characterize the extracted gold nanoparticles. The UV-Vis spectrum showed GNP-absorption peaks at a narrow range of wavelengths, primarily at 520 nm, confirming the formation of gold nanoparticles from the e-waste. The XRD analysis identified the material as metallic gold with characteristic peaks of gold crystals (111), (200), (220), and (311), corresponding to the FCC crystal structure. The SEM and TEM analysis revealed that most of the Au nanoparticles were less than 40 nm in size, with some larger particles resulting from the agglomeration of smaller ones. The EDS spectrum analysis indicated that the gold atoms emitted strong signals. At the same time, other elements such as carbon, oxygen, and metals such as Sn, Zn, Pd, Cu, and Cd showed weaker signals. The recovered gold nanoparticles were found to have a bandgap of 2.2 eV, indicating that they are a direct bandgap semiconductor suitable for use in optoelectronic applications. The environmental impact of the PCBs and the chemicals used in the process were also analyzed to address the necessity of using discarded electronic waste to reduce environmental pollution. The proposed method showed high efficiency for extracting gold nanoparticles from e-waste, with simple process steps, low chemical usage, and low cost, as demonstrated by the results.
Simulation of interlayer coupling for electroactive covalent organic framework design
Authors: Leo Tanner M. , Robbins Megan , Sullivan Alana , Thornes Henry , Fitzsimmons Garrett , Goodey Alyssa , Kowalczyk Tim
Published: May 2024

Porous, stacked two-dimensional covalent organic frameworks (2D COFs) bearing semiconducting linkers can support directional charge transfer across adjacent layers of the COF. To better inform the current and possible future design rules for enhancing electron and hole transport in such materials, an understanding of how linker selection and functionalization affects interlayer electronic couplings is essential. We report electronic structure simulation and analysis of electronic couplings across adjacent linker units and to encapsulated species in functionalized electroactive 2D COFs. The detailed dependence of these electronic couplings on interlayer interactions is examined through scans along key interlayer degrees of freedom and through configurational sampling from equilibrium molecular dynamics on semiempirical potential energy surfaces. Beyond affirming the sensitivity of the electronic coupling to interlayer distance and orientation, these studies offer guidance toward linker functionalization strategies for enhancing charge carrier transport in electroactive 2D COFs.
Continuous pipe-stream self-assembly technology for preparation of high sphericity FOX-7/HMX energetic composite microspheres
Authors: Zhang Xiangyu , Jing Jianquan , Liu Jiaoyang , Zhang Liting , Qi Leixin , An Chongwei
Published: May 2024

The emphasis on producing high-energy and insensitive composite microspheres has increased in energetic materials. However, few methods are available for preparing good spherical and morphological composite microspheres. To produce composite microspheres that are both high-energy and safe, in this article, a continuous pipe-stream self-assembly device was constructed to produce FOX-7/HMX composite microspheres continuously and taking advantage of the principle that PVA and Tween-80 can reduce the surface tension of the microspheres in water. In comparison with the molding powders produced by the kneading way, the FOX-7/HMX composite microspheres prepared by this device had fewer surface defects, a denser structure, a more spherical shape, and a smaller range of particle sizes. The mechanical properties of the pressed columns were better, with maximum compressive strength and strain increased by 44.2% and 21.4%, respectively; and the flowability and bulk density were also improved to some extent (angle of repose: energetic microspheres vs kneading method molding powder, 26.6° vs 51.1°; bulk density: energetic microspheres vs kneading method molding powder, 0.522 vs 0.426 g/cm3). Mechanical sensitivity has also been significantly reduced. This article provides innovative ideas for preparing high-energy and insensitive composite microspheres using a continuous pipe-stream self-assembly device.
Zinc interception and absorption in wheat spikes contribute significantly to grain zinc biofortification
Authors: Hu Naiyue , Gao Zhiqiang , Zhang Wanqing , Du Chenghang , Zhang Yinghua , Zhao Zhigan , Wang Zhimin
Published: May 2024

Context The spike is a crucial organ for intercepting exogenous zinc (Zn) at the late growth stage of wheat (Triticum aestivum L.). However, the role of spikes in wheat biofortification has drawn little attention, and knowledge gaps exist with respect to absorption and translocation of exogenous Zn by wheat. Aims This study aims to determine the role of spikes in wheat biofortification when Zn is applied to the canopy, and to characterise the absorption and translocation of Zn applied to different wheat organs. Methods In two field experiments and one pot experiment, Zn was applied at different stages (heading or early filling stage) to the canopy or to different organs (flag leaf or spike), and Zn concentrations in various organs were determined. Zn interception, Zn absorption, recovery in grain, and translocation amount and rate were calculated. Key results With application to the canopy, the Zn interception rate of spikes was 13% at heading and 28% at early filling. Grain Zn concentration was improved by 17–33% under flag leaf Zn application and 30–37% under spike Zn application, with absorption accounting for 68–90% and 88–99% of Zn applied, respectively. Zn applied at heading was translocated throughout plants before anthesis, and then to spikes. Zn applied at early filling was entirely translocated to spikes. The amount of Zn translocated after flag leaf application and spike application accounted for 16–40% and 13–14% of absorbed Zn, respectively. Conclusions Spikes are critical for intercepting and absorbing exogenous Zn. The Zn absorbed by the spike was more effective for grain Zn biofortification than the Zn absorbed by the flag leaf. Implications The information generated from this study assists in understanding how wheat plants intercept, absorb and translocate Zn.
Arrow of time and gravitational entropy in collapse
Authors: Chakraborty Samarjit , Maharaj Sunil D , Guha Sarbari , Goswami Rituparno
Published: May 2024

We investigate the status of the gravitational arrow of time in the case of a spherical collapse of a fluid that conducts heat and radiates energy. In particular, we examine the results obtained by W. B. Bonnor in his 1985 paper where he found that the gravitational arrow of time was opposite to the thermodynamic arrow of time. The measure of gravitational epoch function P used by Bonnor was given by the ratio of the Weyl square to the Ricci square. In this paper, we have assumed the measure of gravitational entropy (GE) P
1 to be given by the ratio of the Weyl scalar to the Kretschmann scalar. Our analysis indicates that Bonnor’s result seems to be validated, i.e. the gravitational arrow and the thermodynamic arrow of time point in opposite directions. This strengthens the opinion that the Weyl proposal of GE applies only to the Universe as a whole (provided that we exclude the white holes).
Study of the effect of electromagnetic damping force on a magnet oscillating near a non-ferromagnetic conducting plate
Authors: Pal Sanjoy Kumar , Sarkar Soumen , Panchadhyayee Pradipta , Syam Debapriyo
Published: May 2024

We have designed an experiment that involves studying the effects of a conducting plate on the motion of an oscillating disc magnet. We have employed the video analysis method by ‘Tracker’ software to investigate the variation of electromagnetic damping coefficient with distance between the plate and the magnet. This experiment can indeed serve as a valuable educational tool for undergraduate students, covering topics such as damped oscillation, electromagnetic damping, Lenz’s law, and eddy currents.
Frequency-dependent dielectric, electric modulus, and ac conductivity features of Au/n-Si Schottky diodes (SDs) with PVC and (PVC:Graphite/Graphene-Oxide) interlayer
Authors: Altındal Yerişkin S , Taşçıoğlu İ , Badali Y
Published: May 2024

To determine the interlayer effect on dielectric features and conductivity, Au/n-Si (S0), Au/PVC/p-Si (S1), and Au/PVC:Gt-GO/p-Si (S2) type SDs were grown onto the same n-Si wafer and their admittance measurements performed between 100 Hz and 1 MHz. The observed decrease in C and G/ω values as frequency increases shows that the charges at the interface-states (N
ss) can easily follow ac-signal and supply an excess capacitance and conductance at lower frequencies. Using C and G/ω data at 1.5 V, the dielectric-constant (ϵ′), dielectric-loss (ϵ″), and loss-tangent (tan δ) were obtained as a function of frequency. To determine the relaxation processes in (PVC:Gt-GO) nanocomposite, complex-dielectric (M′ and M′′) formalism was also explored in the whole frequency range. The value of ac electrical conductivity (σ
ac) remained independent of frequency until 0.1 MHz and then started to increase exponentially which corresponds to dc and ac conductivity. As compared to S1 and S2 with So SD, the conductivity and ϵ′ values increase due to the PVC and (PVC:Gt-GO) interlayer. The Ln(σ
ac)-Ln(ω) plots were also drawn to analyze the conduction process and their slopes were found as 0.09, 0.39, and 0.58 for S0, S1, and S2 SD, respectively. These results show that the interaction and trap levels of the electron–hole pairs at lower frequencies, as well as from the well-localized relaxation mechanism at higher frequencies.
Perspective: probing elasto-quantum materials with x-ray techniques and in situ anisotropic strain
Authors: Zhang Han , Sanchez Joshua J , Chu Jiun-Haw , Liu Jian
Published: May 2024

Anisotropic lattice deformation plays an important role in the quantum mechanics of solid state physics. The possibility of mediating the competition and cooperation among different order parameters by applying in situ strain/stress on quantum materials has led to discoveries of a variety of elasto-quantum effects on emergent phenomena. It has become increasingly critical to have the capability of combining the in situ strain tuning with x-ray techniques, especially those based on synchrotrons, to probe the microscopic elasto-responses of the lattice, spin, charge, and orbital degrees of freedom. Herein, we briefly review the recent studies that embarked on utilizing elasto-x-ray characterizations on representative material systems and demonstrated the emerging opportunities enabled by this method. With that, we further discuss the promising prospect in this rising area of quantum materials research and the bright future of elasto-x-ray techniques.
Parsing skin effect in a non-Hermitian spinless BHZ-like model
Authors: Halder Dipendu , Basu Saurabh
Published: May 2024

This work comprehensively investigates the non-Hermitian skin effect (NHSE) in a spinless Bernevig-Hughes-Zhang -like model in one dimension. It is generally believed that a system with non-reciprocal hopping amplitudes demonstrates NHSE. However, we show that there are exceptions, and more in-depth analyses are required to decode the presence of NHSE or its variants in a system. The fascinating aspects of our findings, depending on the inclusion of non-reciprocity in the inter-orbital hopping terms, concede the existence of conventional NHSE or NHSE at both edges and even a surprising absence of NHSE. The topological properties and the (bi-orthogonal) bulk-boundary correspondence, enumerated via computation of the (complex) Berry phase and spatial localization of the edge modes, highlight the topological phase transitions occurring therein. Further, to facilitate a structured discussion of the non-Hermitian model, we split the results into

PT

symmetric and non-

PT

symmetric cases with a view to comparing the two.
A novel calibration method based on fixed multi-plane targets for cameras with large field of view
Authors: Shi Xiancong , Peng Tao , Huang Zhenzhen , Zhang Zhijiang
Published: May 2024

For camera calibration with large field of view (FOV), the accuracy is impacted by the size of the calibration targets. Considering the challenges associated with producing and carrying large targets, existing methods resort to using small targets to achieve calibration without high accuracy. In order to solve this problem, a photogrammetric calibration method based on the fixed multi-plane targets (FMPT) is proposed in this paper for cameras with large FOV. The FMPT is composed by multiple identical small planar targets (PTs), with fixed pose transformation relationships among PTs. The proposed calibration method involves the following main steps. Firstly, the camera is moved several times to capture a series of images of FMPT. Secondly, the fixed pose transformation matrices of different small PTs in FMPT are calculated through the initial parameters of camera. Finally, calibration based on photogrammetry is conducted, with a continuous optimization of camera intrinsic and extrinsic parameters based on the multiple 2D and 3D constraint in the FMPT. Simulation and real data experiments show that the calibration accuracy using the proposed method is much higher than that using a small target, and sightly higher than that using a large target. Furthermore, the experiments demonstrate the robust stability of this method, maintaining high calibration accuracy even in the presence of increased noise and error in target production.
Long Term X-Ray Spectral Variations of the Seyfert-1 Galaxy Mrk 279
Authors: Akhila K. , Misra Ranjeev , Ezhikode Savithri H. , Jeena K.
Published: May 2024

We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–2020. We use data from multiple missions – AstroSat, NuSTAR and XMM-Newton, for the purpose. The X-ray spectrum can be modeled as a double Comptonization along with the presence of neutral Fe Kα line emission, at all epochs. We determined the source’s X-ray flux and luminosity at these different epochs. We find significant variations in the source’s flux state. We also investigate the variations in the source’s spectral components during the observation period. We find that the photon index and hence the spectral shape follow the variations only over longer time periods. We probe the correlations between fluxes of different bands and their photon indices, and found no significant correlations between the parameters.
Classification of motor imagery using chaotic entropy based on sub-band EEG source localization
Authors: Bi Jicheng , Gao Yunyuan , Peng Zheng , Ma Yuliang
Published: May 2024

Objective. Electroencephalography (EEG) has been widely used in motor imagery (MI) research by virtue of its high temporal resolution and low cost, but its low spatial resolution is still a major criticism. The EEG source localization (ESL) algorithm effectively improves the spatial resolution of the signal by inverting the scalp EEG to extrapolate the cortical source signal, thus enhancing the classification accuracy. Approach. To address the problem of poor spatial resolution of EEG signals, this paper proposed a sub-band source chaotic entropy feature extraction method based on sub-band ESL. Firstly, the preprocessed EEG signals were filtered into 8 sub-bands. Each sub-band signal was source localized respectively to reveal the activation patterns of specific frequency bands of the EEG signals and the activities of specific brain regions in the MI task. Then, approximate entropy, fuzzy entropy and permutation entropy were extracted from the source signal as features to quantify the complexity and randomness of the signal. Finally, the classification of different MI tasks was achieved using support vector machine. Main result. The proposed method was validated on two MI public datasets (brain–computer interface (BCI) competition III IVa, BCI competition IV 2a) and the results showed that the classification accuracies were higher than the existing methods. Significance. The spatial resolution of the signal was improved by sub-band EEG localization in the paper, which provided a new idea for EEG MI research.
Experimental study on spatial distribution law of traffic noise on urban viaduct
Authors: Li Xingang , Wang Lujie , Ding Yong
Published: May 2024

Traffic noise is the main environmental pollution of the elevated line. In order to prevent and control this noise, it is necessary to understand the spatial distribution of the noise. In this paper, the noise monitoring and data fitting of representative points near the Ningbo viaduct are carried out by means of the field test. By setting measuring points at different distances and heights perpendicular to and parallel to the elevated line, the spatial distribution law of noise near the elevated line is studied. The results show that: (1) The noise in the transverse direction of the bridge decreases in a logarithmic curve with the increase of the vertical distance between the measuring point and the viaduct; (2) The noise along the bridge decreases in a logarithmic curve with the increase of the vertical distance between the measuring point and the intersection; (3) The noise in the elevated direction first increases with the rise of the floor, reaching the maximum on floors 10-12, and the sound pressure on floors 12-20 is basically stable.