bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of AuNs on the optical properties of GaAs/AlGaAs tunnel-coupled quantum well
Authors: Joonhuay Jirarut , van Dommelen Paphavee , Sitpathom Nonthanan 
Published: August 2024

Abstract
Using a numerical approach, we investigated a GaAs/AlGaAs tunnel-coupled quantum well (TCQW) to examine the interplay between electromagnetic waves and gold nanospheres (AuNs) in the presence of an extra SiO2 layer and surface roughness. Our findings demonstrated that the optical efficiency of the response of AuNs was increased in the presence of the SiO2 layer. The extinction cross-section also increased in the presence of surface roughness. Furthermore, we discovered that the orientation of AuNs on the rough surface of TCQW can give rise to a new mode of resonant frequency in the near infrared range. This new mode is advantageous for the TCQW as it is usually seen in AuNs only in the visible range. Lastly, the energy level and wave function of electrons in the TCQW intersubband could be adjusted by an electric field produced by the presence of AuNs. Therefore, this theoretical study could be applied to improve output efficiency and the tuning of performances of optical devices such as solar cells and tunable wavelength photoemitters.
Structure and Photocapacitance characteristics of nanosized coumarin-based dye for organic light-dependent resistor applications
Authors: Althumairi Nouf Ahmed , El-Bashir Samah 
Published: August 2024

Abstract
The performance of a coumarin-based dye as an organic photoresistor, MACROLEX Fluorescent Red G, as an organic photoresistor was investigated. This commercial dye is highly photostable and efficiently fluorescent for solar energy applications. Specifically, this dye possesses several features, including low price, simple processing, and a high fluorescence quantum yield (90%). A comprehensive characterization was conducted using a range of techniques, such as thermogravimetric analysis (TGA), transmission electron microscopy (TEM), optical absorption, and fluorescence spectroscopy. XRD analysis revealed that the material has a polycrystalline triclinic nanostructure, The calculation of the optical band gap indicated a direct interband transition at 2.1 eV, falling within the range of semiconductor materials. Electrical conductivity and photocapacitance measurements were performed using impedance spectroscopy in the frequency range (20Hz-3MHz) at different temperatures (303–473 K). The dye-based device exhibited a significant enhancement in conductance at an illumination intensity of 100 mW cm−2, surpassing its initial value by more than 27 times. This result supports the potential application of this device as an organic light-dependent resistor (OLDR).
Investigating linear and non-linear dynamic characteristics of textured journal bearings with slip boundary condition and pseudoplastic lubricants: a numerical study
Authors: Arif Mohammad , Kango Saurabh , Shukla Dinesh Kumar , Singh Sartaj 
Published: August 2024

Abstract
External excitations and unbalanced rotor forces can increase vibration amplitudes and may also cause the breakdown of continuous liquid lubricant film in hydrodynamic journal bearings. The perfect isolation of the journal-bearing system from these undesirable forces and excitations are difficult. However, recent studies suggest that by utilizing advanced manufacturing techniques, smart coating materials, and highly efficient synthetic lubricants; one can improve the reliability of hydrodynamic lubricant film under such critical operating conditions. In the present study, authors observed the influence of micro-scale textures, low surface energy coatings with slip boundary condition, and pseudoplastic lubricants on the stability margin of hydrodynamic journal bearings. To perform this investigation, the unsteady thermo-hydrodynamic Reynolds equation with considering Elrod cavitation algorithm has been solved. Further, to observe variation in stability margin as compared to conventional bearings, the various dynamic characteristics such as stiffness and damping coefficients, critical mass and critical speed parameters, and journal center trajectory are examined in this study. The findings of the study reveal that slip-texture bearings lubricated with pseudoplastic lubricants are highly beneficial in improving the value of direct and cross stiffness coefficients. In addition, it has been observed that under unsteady operating condition, slip-boundary condition and micro-textures are increasing the isolation of the journal-bearing system and showing efficient control over the unstable motion of the rotating shaft.
Advantage of probabilistic non-Gaussian operations in the distillation of single mode squeezed vacuum state
Authors: Kumar Chandan 
Published: August 2024

Abstract
We consider distillation of squeezing in single mode squeezed vacuum state using three different probabilistic non-Gaussian operations: photon subtraction (PS), photon addition (PA) and photon catalysis (PC). To achieve this, we consider a practical model to implement these non-Gaussian operations and derive the Wigner characteristic function of the resulting non-Gaussian states. Our result shows that while PS and PC operations can distill squeezing, PA operation cannot. Furthermore, we delve into the success probabilities associated with these non-Gaussian operations and identify optimal parameters for the distillation of squeezing. Our current analysis holds significant relevance for experimental endeavors concerned with squeezing distillation.
Propagation properties of the partially coherent radially polarized twisted beam through optical system in turbulence atmosphere
Authors: Qin Yan , Yang Huajun , Yizhi Ma , Wen Guangjun , Huang Yongjun , Liu Jianing , Fu Shuaikang 
Published: August 2024

Abstract
In this paper, the transmission properties of the partially coherent radially polarized twisted (PCRPT) beam propagating in the turbulence atmosphere are investigated. The analytical formulas for the components of the cross-spectral density matrix for the PCRPT beam passing through the optical system in the turbulent atmosphere are developed using the Collins integral and aperture function. Research results indicate that modifying the variable parameters and dimensions of the optical system can control the near-field and far-field distributions of the beam, while providing a more flexible choice of receivers for the PCRPT beam in the receiving plane. By utilizing the Cassegrain reflector system and adjusting the optical system parameters, it is possible to achieve collimated transmission of the PCRPT beam and significantly enhance the beam transmission efficiency in turbulent atmospheric conditions. The derivation process and the research results presented in this paper can be expanded to analyze the application of optical systems to control high-dimensional beam field variations. The envisioned utilization of the results obtained from this research investigation pertains to the fields of beam shaping and optical communications.
Double-image encryption and authentication scheme based on compressed sensing and double random phase encoding
Authors: Xue Linlin , Ge Zenghao , Wang Zhongpeng 
Published: August 2024

Abstract
To enhance the security of image information, a double-image encryption and authentication scheme combining compressive sensing (CS) and double random phase encoding (DRPE) is proposed. First, two plaintext images are taken as real and imaginary parts to form a complex-valued image, which is then encoded using DRPE. Next, extract the phase of the encrypted complex-valued image and encode it into authentication information. Simultaneously, the complex-valued image is sampled using the measurement matrix, which is optimized by Schmidt orthogonalization, and then quantized to form a compressed image. Subsequently, the authentication information is embedded into the compressed image, and by applying the permutation and diffusion algorithm to it, the ciphertext image is obtained. At the receiving end, the ciphertext is decrypted using inverse permutation and inverse diffusion algorithms, and the authentication information is decoded to acquire the authentication image. Finally, synchronous authentication of the two reconstructed images is achieved using a nonlinear cross-correlation method. Additionally, the keys in the proposed scheme are generated using high-dimensional chaotic systems, effectively reducing the required storage space and transmission bandwidth. Simulation results demonstrate that the proposed scheme has high image reconstruction performance at different compression ratios and possesses outstanding security and authentication capabilities.
On the reconstruction of cardiac transmembrane potential pattern from body surface measurement
Authors: Zhang Qiang , Wang Liyan , Liu Jijun 
Published: August 2024

Abstract
Electrocardiographic imaging (ECGI) is a diagnostic tool designed for the noninvasive detection of electrical activity in the heart. Mathematically, this imaging process can be modelled by an inverse problem for the coupled elliptic system with Cauchy data. For the bidomain model describing the electrical activity in the myocardium, we reconstruct the transmembrane potential on the heart surface from ECG recordings. The reconstruction process is split into two steps: firstly computing the electrical potential and current on heart surface from torso surface recordings and then recovering the transmembrane potential on the heart surface. The first step is essentially a Cauchy problem for elliptic equation which is well-known to be severely ill-posed. We realize this step in terms of boundary integral system by a quasi-regularization scheme to deal with the ill-posedness. The second step is implemented by an integral equation of the second kind with nontrivial null space. We remove the non-uniqueness and then provide a numerical scheme by the boundary element method to obtain the transmembrane potential on the heart surface. The regularized solution obtained from noisy measurement data is proven rigorously to be convergent to the exact solution as the measurement error in the torso surface tends to zero. For solving the regularizing system numerically, we establish quadrature formulas for boundary potentials for 3-dimensional bio-tissue in terms of the concept of solid angles. The numerical realizations for different configurations are finally presented to show the validity of the proposed scheme.
A preliminary study exploring the effects of transcutaneous spinal cord stimulation on spinal excitability and phantom limb pain in people with a transtibial amputation
Authors: Dalrymple Ashley N , Fisher Lee E , Weber Douglas J 
Published: August 2024

Abstract

Objective. Phantom limb pain (PLP) is debilitating and affects over 70% of people with lower-limb amputation. Other neuropathic pain conditions correspond with increased spinal excitability, which can be measured using reflexes and F-waves. Spinal cord neuromodulation can be used to reduce neuropathic pain in a variety of conditions and may affect spinal excitability, but has not been extensively used for treating PLP. Here, we propose using a non-invasive neuromodulation method, transcutaneous spinal cord stimulation (tSCS), to reduce PLP and modulate spinal excitability after transtibial amputation. Approach. We recruited three participants, two males (5- and 9-years post-amputation, traumatic and alcohol-induced neuropathy) and one female (3 months post-amputation, diabetic neuropathy) for this 5 d study. We measured pain using the McGill Pain Questionnaire (MPQ), visual analog scale (VAS), and pain pressure threshold (PPT) test. We measured spinal reflex and motoneuron excitability using posterior root-muscle (PRM) reflexes and F-waves, respectively. We delivered tSCS for 30 min d−1 for 5 d. Main Results. After 5 d of tSCS, MPQ scores decreased by clinically-meaningful amounts for all participants from 34.0 ± 7.0–18.3 ± 6.8; however, there were no clinically-significant decreases in VAS scores. Two participants had increased PPTs across the residual limb (Day 1: 5.4 ± 1.6 lbf; Day 5: 11.4 ± 1.0 lbf). F-waves had normal latencies but small amplitudes. PRM reflexes had high thresholds (59.5 ± 6.1 μC) and low amplitudes, suggesting that in PLP, the spinal cord is hypoexcitable. After 5 d of tSCS, reflex thresholds decreased significantly (38.6 ± 12.2 μC; p < 0.001). Significance. These preliminary results in this non-placebo-controlled study suggest that, overall, limb amputation and PLP may be associated with reduced spinal excitability and tSCS can increase spinal excitability and reduce PLP.
Laplacian renormalization group: an introduction to heterogeneous coarse-graining
Authors: Caldarelli Guido , Gabrielli Andrea , Gili Tommaso , Villegas Pablo 
Published: August 2024

Abstract
The renormalization group (RG) constitutes a fundamental framework in modern theoretical physics. It allows the study of many systems showing states with large-scale correlations and their classification into a relatively small set of universality classes. The RG is the most powerful tool for investigating organizational scales within dynamic systems. However, the application of RG techniques to complex networks has presented significant challenges, primarily due to the intricate interplay of correlations on multiple scales. Existing approaches have relied on hypotheses involving hidden geometries and based on embedding complex networks into hidden metric spaces. Here, we present a practical overview of the recently introduced Laplacian RG (LRG) for heterogeneous networks. First, we present a brief overview that justifies the use of the Laplacian as a natural extension of well-known field theories to analyze spatial disorder. We then draw an analogy to traditional real-space RG procedures, explaining how the LRG generalizes the concept of ‘Kadanoff supernodes’ as block nodes that span multiple scales. These supernodes help mitigate the effects of cross-scale correlations due to small-world properties. Additionally, we rigorously define the LRG procedure in momentum space in the spirit of the Wilson RG. Finally, we show different analyses for the evolution of network properties along the LRG flow following structural changes when the network is properly reduced.
A functional renormalization group for signal detection and stochastic ergodicity breaking
Authors: Erbin Harold , Finotello Riccardo , Wahabou Kpera Bio , Lahoche Vincent , Ousmane Samary Dine 
Published: August 2024

Abstract
Signal detection is one of the main challenges in data science. As often happens in data analysis, the signal in the data may be corrupted by noise. There is a wide range of techniques that aim to extract the relevant degrees of freedom from data. However, some problems remain difficult. This is notably the case for signal detection in almost continuous spectra when the signal-to-noise ratio is small enough. This paper follows a recent bibliographic line, which tackles this issue with field-theoretical methods. Previous analysis focused on equilibrium Boltzmann distributions for an effective field representing the degrees of freedom of data. It was possible to establish a relation between signal detection and

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-symmetry breaking. In this paper, we consider a stochastic field framework inspired by the so-called ‘model A’, and show that the ability to reach, or not reach, an equilibrium state is correlated with the shape of the dataset. In particular, by studying the renormalization group of the model, we show that the weak ergodicity prescription is always broken for signals that are small enough, when the data distribution is close to the Marchenko–Pastur law. This, in particular, enables the definition of a detection threshold in the regime where the signal-to-noise ratio is small enough.
50 years of mining-induced environmental changes: topography, hydrology, and vegetation health in Kazreti, Georgia
Authors: Avkopashvili M , Avkopashvili I , Avkopashvili G , Ayo-Bali A E 
Published: August 2024

Abstract
Globally, prioritizing short-term economic gains from mineral extraction has led to a critical dilemma: a planet rich in resources struggles with environmental degradation and a diminishing ability to sustain future generations. Open-pit mining exemplifies this paradox, causing significant environmental damage. In Georgia, this extractive industry presents environmental problems. Despite these known consequences, the long-term impacts of mining activities remain understudied. This study addressed this gap by analyzing the effects of open-pit mining on terrain morphology, and water dynamics in the Kazreti region over a 50-year period (1970–2020) and vegetation health over 35-year period (1987–2022). By integrating water quality assessment, spatial analysis and remote sensing, we revealed the significant human-induced changes to the region’s ecosystem. Spatial analysis results suggested that over 156.7 million cubic meters of bedrock have been fragmented by mining in southern East Georgia, with 125.5 million cubic meters deposited in valleys. Consequently, discernible shifts in the trajectories of water flow were observed based on the hydrological model. Additionally, a comparative analysis of NDVI and EVI values revealed a decline in vegetation health near mining zones, while remote forest areas remained stable. June typically showed healthier vegetation due to cooler temperatures and optimal growing conditions, while August presented lower vegetation health due to increased heat stress. Water quality revealed significant loadings of Cu (58–1855 μg l−1), Zn (54–2582 μg l−1), Mn (1–2167 μg l−1), and Cd (0.1–4.5 μg l−1), in local river systems, which are higher than the Georgian official guideline values (Cu - 1000, Zn - 1000, Mn—100, Cd—1 μg l−1). This study highlighted the need for a broader long-term monitoring strategy to assess the migration of these contaminants within the food web and the consequent socio-economic impact.
A fully integrated electronic fabric-enabled multimodal flexible sensors for real-time wireless pressure-humidity-temperature monitoring
Authors: Zhao Yunlong , Yuan Yangbo , Zhang Haiyan , Chen Zijian , Zhao Haitao , Wu Guirong , Zheng Weihao , Xue Chenyang , Yin Zongyou , Gao Libo 
Published: August 2024

Abstract
Real-time physiological information monitoring can predict and prevent disease, or improve treatment by early diagnosis. A comprehensive and continuous monitoring of human health requires highly integrated wearable and comfortable sensing devices. To address this need, we propose a low-cost electronic fabric-enabled multifunctional flexible sensing integration platform that includes a flexible pressure sensor for monitoring postural pressure, a humidity sensor for monitoring the humidity of the skin surface, and a flexible temperature sensor for visualizing the ambient temperature around the human body. Thanks to the unique rough surface texture, hierarchical structure, and robust electromechanical features of the MXene-modified nonwoven fabrics, the flexible pressure sensor can achieve a monitoring sensitivity of 1529.1 kPa−1 and a pressure range of 150 kPa, which meets the demand for human pressure detection. In addition, the unique porous structure of the fabric and the stacked multilayer structure of MXene enable the humidity sensor to exhibit extremely high monitoring sensitivity, even through clothing, and still be able to detect the humidity on the skin surface. Temperature sensors based on screen-printed thermochromic liquid crystals enable visual monitoring in the range of 0 °C–65 °C. Through further integration with flexible printed circuit board circuits, we demonstrate a proof-of-concept device that enables real-time monitoring of human physiological information such as physical pressure, humidity, and ambient temperature environment, suggesting that the device provides an excellent platform for the development of commercially viable wearable healthcare monitors.
A label-free sensing of creatinine using radio frequency-driven lab-on-chip (LoC) system
Authors: Zahra Andleeb , Sinha Swarnim , Modak Alimpan , Siddiqui Imran , Azeemuddin Syed , Bhimalapuram Prabhakar , Sau Tapan Kumar , Kumar Pawan , Abbas Zia 
Published: August 2024

Abstract
This paper presents a promising avenue of Radio Frequency (RF) biosensors for sensitive and real-time monitoring of creatinine detection. Knowing creatinine levels in the human body is related to its possible association with renal, muscular, and thyroid dysfunction. The detection was performed using an Inter-Digitated Capacitor (IDC) made of copper (Cu) metal over an FR4 substrate. To demonstrate our methodology, we have chosen Phosphate Buffer (PB) as our solvent for making the creatinine solutions of different concentrations. Moreover, Assayed Chemistry Control (ACC), a reference control consisting of human serum-based solutions has been mixed with the different concentrations of creatinine in a ratio of 1:9 to spike the creatinine value in the ACC solution. The sensor has been designed using a High-Frequency Structure Simulator (HFSS) tool with an operating frequency of 2.53 GHz. Then the design is fabricated over the FR4 printed circuit board (PCB) and tested using a Vector Network Analyzer (VNA). However, the sensitive area of the IDC is introduced to grade 4 Whatman filter paper for the Sample Under Test (SUT) handling unit. The main advantage of using Whatman filter paper is that the uniform spreading of liquid reduces experimental error, and less volume is required for testing the sample. The principal idea implemented in the biosensor design is to track the shift in the operating frequency in the presence of different concentrations of creatinine mix in ACC solution with Phosphate Buffer (PB) solution as a reference.
Curved HSIW: an affordable performance for non-planar millimeter-wave applications
Authors: Savvides Giorgos , Zhang Weijia , Qiu Dan , Oberhammer Joachim , Robertson Ian D , Chudpooti Nonchanutt , Somjit Nutapong 
Published: August 2024

Abstract
This paper introduces a Curved Hollow Substrate Integrated Waveguide (CHSIW) to address the growing demand for millimeter-wave applications, including communication, sensing, imaging, radar, and wireless power transfer systems. Leveraging advancements in integrated circuits and system-in-package (SiP) technology, the CHSIW tackles the challenges associated with hardware integration into curved structures. The design utilizes MultiJet Printing (MJP) for the M3 crystal dielectric substrate and a water laser cutter system for copper sheets, streamlining the fabrication process by eliminating complex via manufacturing steps through prefabricated through-hole vias. Operating in the frequency range of 21.7 GHz to 32 GHz, the CHSIW exhibits outstanding performance on curved surfaces, with measured average attenuation constants of 1.89 Np m−1 (16.42 dB m−1) and 1.95 Np m−1 (16.94 dB/m) for samples with radii of curvature of 166.8 mm and 125.1 mm, respectively. Beyond addressing technical challenges, the CHSIW presents a cost-effective and simplified fabrication process, positioning it as a breakthrough solution for diverse millimeter-wave applications, including future robotic and UAV communications. Furthermore, the proposed design and fabrication technique hold promise for the realization of conformal and free-form Hollow Substrate Integrated Waveguide (HSIW) devices in the future.