bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detecting elevated left ventricular end diastolic pressure from simultaneously measured femoral pressure waveform and electrocardiogram
Authors: Pahlevan Niema M , Alavi Rashid , Liu Jing , Ramos Melissa , Hindoyan Antreas , Matthews Ray V 
Published: July 2024

Abstract

Objective. Instantaneous, non-invasive evaluation of left ventricular end-diastolic pressure (LVEDP) would have significant value in the diagnosis and treatment of heart failure. A new approach called cardiac triangle mapping (CTM) has been recently proposed, which can provide a non-invasive estimate of LVEDP. We hypothesized that a hybrid machine-learning (ML) method based on CTM can instantaneously identify an elevated LVEDP using simultaneously measured femoral pressure waveform and electrocardiogram (ECG). Approach. We studied 46 patients (Age: 39–90 (66.4 ± 9.9), BMI: 20.2–36.8 (27.6 ± 4.1), 12 females) scheduled for clinical left heart catheterizations or coronary angiograms at University of Southern California Keck Medical Center. Exclusion criteria included severe mitral/aortic valve disease; severe carotid stenosis; aortic abnormalities; ventricular paced rhythm; left bundle branch and anterior fascicular blocks; interventricular conduction delay; and atrial fibrillation. Invasive LVEDP and pressure waveforms at the iliac bifurcation were measured using transducer-tipped Millar catheters with simultaneous ECG. LVEDP range was 9.3–40.5 mmHg. LVEDP = 18 mmHg was used as cutoff. Random forest (RF) classifiers were trained using data from 36 patients and blindly tested on 10 patients. Main results. Our proposed ML classifier models accurately predict true LVEDP classes using appropriate physics-based features, where the most accurate demonstrates 100.0% (elevated) and 80.0% (normal) success in predicting true LVEDP classes on blind data. Significance. We demonstrated that physics-based ML models can instantaneously classify LVEDP using information from femoral waveforms and ECGs. Although an invasive validation, the required ML inputs can be potentially obtained non-invasively.
Energy efficient F atom generation and control in CF4 capacitively coupled plasmas driven by tailored voltage waveforms
Authors: Wang Xiao-Kun , Masheyeva Ranna , Liu Yong-Xin , Song Yuan-Hong , Hartmann Peter , Donkó Zoltán , Schulze Julian 
Published: July 2024

Abstract
Neutral radicals generated by electron impact dissociation of the background gas play important roles in etching and deposition processes in low pressure capacitively coupled plasmas (CCPs). The rate and energy efficiency of producing a given radical depend on the space- and time-dependent electron energy distribution function (EEDF) in the plasma, as well as the electron energy dependent cross sections of the electron-neutral collisions that result in the generation of the radical. For the case of a CCP operated in CF4 gas, we computationally demonstrate that the energy efficiency of generating neutral radicals, such as F atoms can be improved by controlling the EEDF by using tailored voltage waveforms (TVW) instead of single-frequency driving voltage waveforms and that separate control of the radical density and the ion energy can be realized by adjusting the waveform shape at constant peak-to-peak voltage. Such discharges are often used for industrial etching processes, in which the F atom density plays a crucial role for the etch rate. Different voltage waveform shapes, i.e. sinusoidal waveforms at low (13.56 MHz) and high (67.8 MHz) frequencies, peaks- and sawtooth-up TVWs, are used to study their effects on the energy cost / energy efficiency of F atom generation by PIC/MCC simulations combined with a stationary diffusion model. The F atom density is enhanced by increasing the voltage amplitude in the single frequency cases, while the energy cost per F atom generation increases, i.e. the energy efficiency decreases, because more power is dissipated to the ions, as the sheath voltages and the ion energy increase simultaneously. In contrast, using TVWs can result in a lower energy cost and provide separate control of the F atom density and the ion energy. This is explained by the fact that tailoring the waveform shape in this way allows to enhance the high-energy tail of the EEDF during the sheath expansion phase by inducing a non-sinusoidal sheath motion, which results in acceleration of more electrons to high enough energies to generate F atoms via electron-neutral collisions compared to the single frequency cases. Similar effects of TVWs are expected for the generation of other neutral radicals depending on the electron energy threshold and the specific consequences of TVWs on the EEDF under the discharge conditions of interest.
Exploring low temperature-sputtered indium tin oxide (ITO) as an anti-reflection layer for silicon solar cells
Authors: Mohd Ahir Zon Fazlila , Mohd Rais Ahmad Rujhan , Ahmad Ludin Norasikin , Sopian Kamaruzzaman , Sepeai Suhaila 
Published: July 2024

Abstract
This paper tackles challenges in silicon (Si) solar cells, specifically the use of hazardous Phosphorus Oxychloride (POCl3) for emitter formation and silane/ammonia for the Anti-Reflective Coating (ARC) layer, accompanied by high-temperature metallization. The study proposes an eco-friendly ARC layer process, replacing toxic materials. Indium Tin Oxide (ITO) with a refractive index of ∼2.0 is suggested as a non-toxic substitute for SiN
x
in the ARC layer. ITO enables fine-tuning of optical parameters and, with its electrical properties, supports low-resistivity contacts through efficient, low-temperature metallization processes. ITO-passivated solar cells with Ag polymer paste as a front contact exhibit promising characteristics: a commendable photocurrent density (J
sc) of 20 mA cm−2 at 850 °C, low series resistance (R
s) of 1.9 Ω, and high shunt resistance (R
shunt) of 28.9 Ω, as demonstrated by illuminated I–V measurements. Implementing ITO as the ARC on a less toxic emitter junction enhances Si solar cells’ current density gain, minimizing current leakage during high-temperature processing. In conclusion, adopting less toxic materials and employing low-temperature processing in passive silicon solar cell fabrication presents an attractive alternative for cost reduction and contributes to environmentally sustainable practices in green manufacturing.
Disentangling different interfacial effects of reduced thin layer magnetizations
Authors: Ilse Sven Erik , Nacke René , Schütz Gisela , Goering Eberhard 
Published: July 2024

Abstract
Thin buried magnetic layers ranging from thicknesses of a few atomic monolayers to several nanometers are omnipresent in the fields of magnetism and spintronics. For the functionality and fine tuning of devices build with such layers, exact knowledge of the depth dependent magnetic properties is essential. Especially the interfacial magnetic properties are important. Hence, understanding how magnetism is affected by structural variations, such as thickness or interface roughness, is mandatory. In this study, we use x-ray resonant magnetic reflectometry and magnetometry to study the high-resolution depth dependent magnetization profiles of thin magnetic transition metal layers sandwiched between an oxide and chromium layer. Compared to bulk materials, the room temperature saturation magnetization of these layers is reduced by up to 67%. These reductions are extremely sensitive to small structural variations. From the magnetic depth profiles, we disentangle different effects contributing to the magnetization reduction and the exact magnetic properties of the interface.
Design and optimization of (FA)2BiCuI6-based double perovskite solar cells using kesterite CBTS as hole transport layer for high power conversion and quantum efficiency
Authors: Yadav Shivangi , Lohia Pooja , Sahu Anupam , Chaudhary Akhilesh Kumar 
Published: July 2024

Abstract
This work introduces the design of a novel architecture for double perovskite solar cells (DPSCs) utilizing (FA)2BiCuI6, known for its enhanced stability relative to single perovskite materials for production of efficient, ultra-thin solar cells. The proposed architecture features a unique device configuration of ITO/WO3/(FA)2BiCuI6/Cu2BaSnS4/W, incorporating a Kesterite type Cu-based quaternary chalcogenide material, Cu2BaSnS4 known as CBTS, is used as hole transport layer (HTL) with a bandgap of 1.9 eV, WO3 as the electron transport layer (ETL) with a 2.6 eV bandgap, and (FA)2BiCuI6 as the absorber layer with a 1.55 eV bandgap. The study provides an in-depth theoretical analysis of the energy band structure, defects, and quantum efficiency of the DPSC, highlighting the device’s post-optimization photovoltaic parameters. Remarkably, the optimized DPSC demonstrated superior performance with a PCE of 24.63%, Voc of 1.16 V, Jsc of 25.67 mA cm−2, and FF of 82.87%. The research also explores the effects of various factors on photovoltaic performance, including temperature, interface defect, and generation and recombination rates, as well as work function of back contact materials. The results underscore the exceptional potential of (FA)2BiCuI6, especially when combined with the HTL CBTS, in significantly reducing sheet resistance and enhancing the overall performance of solar cells. The design is validated using the SCAPS-1D simulation software tool.
Single crystalline Holmium doped InSe for optical limiting operation in Near-IR region
Authors: Yildiz Elif Akhuseyin 
Published: July 2024

Abstract
Single crystals possessing nonlinear absorption (NA) character are favorable optical limiter in near infrared region (NIR). The NA features of pure and 0.005%, 0.05%, 0.1% Holmium (Ho) doped single crystals of InSe were analyzed at 1200 nm wavelength within 120 fs and 1 kHz repetition rate. The open-aperture Z-scan technique was employed to determine the NA performance and optical limiting-(OL) threshold. In an attempt to determine the NA coefficients, two types of theoretical models were used. The first model takes into account only the two photon absorption-(TPA), while the second model considers one photon absorption, TPA and free carrier absorption. Based on the experimental results, the main NA mechanism of the studied single crystals is determined as sequential TPA. TPA coefficient value of the pure InSe single crystal increased from 1.41 × 10−10 to 10.7 × 10−10 cm W−1 with increasing Ho doping concentration at 398.1 GW cm−2 input intensity. The NA coefficients increased from 0.84 × 10−9 to 1.62 × 10−9 cm W−1 at the same input intensity. On the other hand, the OL threshold values were found to be 0.027, 0.025, 0.022 and 0.020 J cm−2 at 1200 nm wavelength for pure InSe and the increasing Ho concentration, respectively. The robust NA characteristics and the low OL threshold establish the Ho-doped InSe single crystal as a favorable candidate for OL applications in the NIR spectral region.
Boosting the efficiency of an inverted structure halide perovskite solar cell: a numerical investigation
Authors: Tlili Wahiba , Bouazizi Sarra , Kadri Bassem , Bouich Amal , Issaoui Rabeb , Ghrissi Alia , Amlouk Mosbah , Omri Ahmed 
Published: July 2024

Abstract
Inverted solar cells have attracted significant attention because they have low hysteresis and are resistant to environmental variables, such as oxygen and humidity, making them more stable and long-lasting. Herein, we investigate the performance optimisation of an inverted design based on MAPbI3-xClx with the structure ITO/PTAA/MAPbI3-xClx/PC60BM/BCP/Ag by utilising SCAPS-1D, a simulation tool. Accordingly, a substantial improvement in efficiency can be achieved by optimising several factors linked to each layer’s performance in a perovskite solar cell (PSC). Total defect density, work function, thickness, and electron affinity have a significant impact on the photovoltaic response. Specifically, the impact of optimisation of the charge transport layers and the perovskite layer on the device’s performance parameters was discussed, resulting in a milestone within a remarkable increase in PCE of 21.59%, whereas the original structure’s efficiency was 6.9%. Additionally, it has been shown that aluminium can substitute silver in the top electrode of a solar cell without affecting its efficiency, allowing the development of cost-effective solar cells. The present study provides an insight in the creation of a highly stable low-cost and higher-efficiency perovskite solar cell.
Phonon-assisted leakage current of InGaN light emitting diode
Authors: Grinys Tomas , Razas Kristupas , Podlipskas Žydrūnas , Bukauskas Virginijus , Stanionytė Sandra 
Published: July 2024

Abstract
We report on the leakage current mechanism in a blue GaN-based light-emitting diode (LED). The device structure was grown by the MOCVD technique on a sapphire substrate. The LED was characterized through various measurements including current-voltage, electroluminescence, and secondary ion mass spectroscopy (SIMS). Capacitance-voltage measurements were employed to calculate the depletion layer thickness at different bias voltages and to analyze the doping profile in the active layer. The reverse temperature-dependent current-voltage measurements were carried out to study the leakage mechanism. The leakage current was explained by phonon-assisted tunneling of charge carriers through deep trap states. The trap energy and density of states were extracted from the application of the introduced model. Cathodoluminescence measurements were performed to evaluate the density of dislocations, which were then compared to x-ray diffraction measurements. The determined value was close to the density of states obtained from the tunneling model.
Machine learning validated compact circularly polarized dual port-MIMO antenna with polarization diversity for ku-band applications
Authors: M N Manjunath , Singh Vivek , Dwivedi Ajay Kumar , Pandey Stuti 
Published: July 2024

Abstract
A novel dual Port C-Shape MIMO broadband printed antenna with wide axial ratio bandwidth (ARBW) is modelled and built for Ku band Applications. The unit cell of the proposed antenna has a compact size of 25 × 26 × 0.8 mm3 engraved on RT duriod 5880 material (ε
r = 2.2, thickness of 0.8 mm). The proposed model consists of C shaped radiator, plus symbol structure and a modified ground plane. The machine learning concept is used to investigate the dimensional dependency of the plus sign on the CP behaviour. The suggested antenna shows impedance bandwidth (−10 dB) and 3-dB ARBW of 6 GHz (12 GHz to 18 GHz) which is covering the whole Ku band. The diversity performance parameters and antenna parametric investigation is also carried out to justify the MIMO identity of the proposed design. The simulated and measured counterparts are found in harmony. The strength of the proposed antenna is its planar structure, wide ARBW, polarization diversity, and wide operating Ku bandwidth.
Visually security privacy medical data protection scheme using compressive sensing and improved duffing chaotic system
Authors: Huang Shufeng , Jiang Donghua , Huang Linqing , Xiong Xiaoming , Tan Beihai , Cai Shuting 
Published: July 2024

Abstract
Health and medical data frequently contain sensitive patient information that must be protected. Existing visual security schemes for medical images exhibit limitations in the imperceptibility of cipher images and the performance of image reconstruction. This paper introduces and evaluates a novel approach called Visual Meaningful Image Encryption (VMIE) for securing medical images. The proposed VMIE scheme employs a chaotic system based on the Duffing equation for initial encryption. Medical images are processed and encrypted in a sparse domain. A Bidirectional Chaotic Magic Transformation (BCMT) algorithm is then applied to scramble the sparse medical images. The scrambled data undergoes compression and diffusion. An adaptive embedding strategy employing the Discrete Cosine Stockwell Transform (DCST) integrates confidential data into the host image. The performance of the proposed chaotic system is validated through theoretical analysis and numerical simulation. Simulation results, along with comparisons to existing schemes, demonstrate the efficacy of the VMIE method in enhancing visual security and its suitability for natural images. The VMIE approach presented in this paper offers a promising solution for securing medical images, effectively addressing the limitations of current visual security schemes.
Understanding magnetic interactions in SrFe12O19/CoFe2O4 nanocomposites: role of particle structure on exchange spring magnet behaviour
Authors: Idayanti N , Sugandi G , Kristiantoro T , Sudrajat N , Mulyadi D , Nuruddin A , Dedi  , Manaf A 
Published: July 2024

Abstract
This study explores the impact of particle structure on the magnetic properties of SrFe12O19/CoFe2O4 nanocomposites. The investigation focuses on variations in particle sizes of SrFe12O19 (SHF) and CoFe2O4 (COF) with a mass ratio of 80:20, considering micro-scale poly-crystallite particles (Pp) and nano-scale mono-crystallite particles (Mp). Four sample structures (COM1, COM2, COM3, COM4) were prepared, each with different combinations of poly-crystallite and mono-crystallite particles. Morphological analysis through scanning electron microscopy and energy-dispersive x-ray spectroscopy revealed consistent grain shape and size post-sintering. Magnetic properties analysis using Permagraph indicated that grain fineness and uniformity influence the resulting magnetic properties, with composite samples featuring nano-sized hard or soft phases showing improved M

r
, M

s
, and (BH)
max values compared to individual phases. The nanocomposite sample COM4, characterized by fine and uniform particle size, exhibited the highest remanence magnetization, M

r
(34.55 emu g−1), saturation magnetization, M
s (66.44 emu g−1), and the maximum energy product, (BH)
max (1.17 MGOe).
Spectral distortions from acoustic dissipation with non-Gaussian (or not) perturbations
Authors: Sharma Devanshu , Lesgourgues Julien , Byrnes Christian T. 
Published: July 2024

AbstractA well-known route to form primordial black holes in the early universe relies on the existence of unusually large primordial curvature fluctuations, confined to a narrow range of wavelengths that would be too small to be constrained by Cosmic Microwave Background (CMB) anisotropies. This scenario would however boost the generation ofμ-type spectral distortions in the CMB due to an enhanced dissipation of acoustic waves. Previous studies ofμ-distortion bounds on the primordial spectrum were based on the assumptions of Gaussian primordial fluctuations. In this work, we push the calculation ofμ-distortions to one higher order in photon anisotropies. We discuss how to derive bounds on primordial spectrum peaks obeying non-Gaussian statistics under the assumption of local (perturbative or not) non-Gaussianity. We find that, depending on the value of the peak scale, the bounds may either remain stable or get tighter by several orders of magnitude, but only when the departure from Gaussian statistics is very strong. Our results are translated in terms of bounds on primordial supermassive black hole mass in a companion paper.
Thermalization of one-dimensional classical lattices: beyond the weakly interacting regime
Authors: Wang 王 Zhen 振 , Fu 符 Weicheng 维成 , Zhang 张 Yong 勇 , Zhao 赵 Hong 鸿 
Published: July 2024

Abstract
Thermalization in many-body systems, especially with strong interactions, is a central question in physics. In this work, we present a novel framework for the thermalization of interacting wave systems, distinguishing between trivial (no momentum exchange) and nontrivial interactions (significant energy redistribution). This distinction leads to a statistically equivalent model with weakened interactions. By applying this to FPUT-like models, we identify a unique double scaling of thermalization times. Crucially, our findings suggest the persistence of prethermalization in strong interactions.
The Downscaling-Upscaling Method for Load Prediction Based on Feature Prediction and Curve Clustering
Authors: Liu Ben , Dong Danhuang , Feng Yi , Lan Zhou , Zhang Peng 
Published: July 2024

Abstract
Load forecasting, as a classical problem, exhibits decreased accuracy in existing algorithms when the prediction window lengthens. This paper proposes a novel approach based on a downscaling-upscaling paradigm. In the downscaled process, the daily minimum load and the daily total load sequence are extracted from the load sequence. These two features are predicted using piecewise linear regression. The upscaling process involves clustering the daily load curves into multiple clusters using the K-means clustering method. The centroids of each cluster form a standard load curve library. During prediction, a standard load curve is selected from the library based on the daily load curve of the current day, and the final daily load curve prediction is obtained by applying translation and scaling operations. The translation and scaling parameters are determined by the predicted daily minimum load, predicted daily total load, and the daily load curve of the current day. Experimental results demonstrate that the proposed method achieves superior accuracy compared to existing methods for long prediction window widths.
Influence of SF6/N2 Mixed Gas Pressure on the Arc Control Ability of the Main Electrode in the Trigger Gap
Authors: Zhao Zhen , Dong Enyuan , Zhang Yifan , Li Zhibing , Zhou Ziyi , Song Yu 
Published: July 2024

Abstract
In the controllable self-recovery energy-absorbing apparatus of the Baihetan-Jiangsu Hybrid UHVDC Transmission Project, a 30%SF6/70%N2 mixed gas is employed as the insulating medium within the trigger gap switch. In order to mitigate surface erosion on the main electrode of the trigger gap switch, as well as the inner wall of the insulating sleeve, and to reduce the usage of SF6, an investigation into the arc control ability of the main electrode under different pressures of the mixed gas has been initiated. The motion characteristics of the arc within the gap have been simulated using a Magnetohydrodynamics (MHD) model, and the variation pattern of the main electrode’s arc control ability within the pressure range of 0.1MPa to 0.4MPa was obtained by analyzing the changes in the arc volume. The arc control ability of the main electrode is influenced by the differences in physical parameters of mixed gas at different pressures. Results indicate that the electrode’s arc control ability experiences an initial increase followed by a subsequent decrease with the rising pressure of 30%SF6/70%N2 mixed gas. Notably, within the pressure range of 0.1MPa to 0.4MPa, the main electrode exhibits the highest arc control ability when the pressure of the mixed gas is 0.3MPa.
Practical Method for Voltage Control in Active Distribution Network Based on Sensitivity
Authors: Huang Sujuan , Zhou Xun , Shen Jiangbo 
Published: July 2024

Abstract
The access of a large number of distributed photovoltaic power stations makes the voltage problem of the distribution network more prominent, but also provides controllable resources for the distribution network. In order to exploit the regulation potential of distributed photovoltaic power stations in active distribution networks, a practical method for voltage control based on sensitivity is proposed. The adjustment nodes and adjustment amounts are determined according to sensitivity. Based on the power flow equation, the voltage sensitivity calculation is appropriately simplified to reduce the amount of calculation. By combining forecast data and network topology, a control architecture for parallel calculation of sensitivity analysis, reactive power regulation capacity analysis, and real-time voltage control is proposed. This architecture decouples sensitivity calculation from real-time regulation and control, improving the processing speed and reliability of real-time voltage regulation and control. A case study based on a 10kV distribution network in a certain area shows that although the proposed sensitivity calculation method has some deviation, it can meet the requirements of engineering practicality and effectively achieve voltage over-limit control.