bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational screening of phytochemicals present in some Nigerian medicinal plants against sickle cell disease
Authors: Asibor Yemisi Elizabeth , Oyebamiji Abel Kolawole , Latona Dayo Felix , Semire Banjo
Published: November 2024

Four hundred Phytochemical (bio-active) compounds having predictive activity for treating Sickle Cell Anemia were screened, using PASS online computational resource. Twenty-six compounds out of the four hundred compounds which showed high probability for treating sickle were further screened for pharmacokinetics profiles (ADMET properties) using SwissAdmet, AdmetSAR 2 and Pro-tox II online resources. Only thirteen compounds that displayed good ADMET properties from the twenty-six were further used for DFT calculations and molecular docking against carbonmonoxy sickle hemoglobin (PDB ID: 5E6E). Molecular docking analysis reinforced by DFT calculations showed that two compounds, phenanthrene-5,6-dione (A9) and 2-(3,4-dihydroxyphenyl)-5,7-dihydroxychromen-4-one (A13, Luteolin) had the best binding affinity of  − 8.3 and − 8.9 kcal/mol, respectively, compared to voxelotor (GBT-440), a drug use in treating sickle cell disease. Molecular dynamic simulations showed that 2-(3,4-dihydroxyphenyl)-5,7-dihydroxychromen-4-one (A13, Luteolin) is highly stable with the protein than voxelotor.
Ensemble based high performance deep learning models for fake news detection
Authors: E.Almandouh Mohammed , Alrahmawy Mohammed F. , Eisa Mohamed , Elhoseny Mohamed , Tolba A. S.
Published: November 2024

Social media has emerged as a dominant platform where individuals freely share opinions and communicate globally. Its role in disseminating news worldwide is significant due to its easy accessibility. However, the increase in the use of these platforms presents severe risks for potentially misleading people. Our research aims to investigate different techniques within machine learning, deep learning, and ensemble learning frameworks in Arabic fake news detection. We integrated FastText word embeddings with various machine learning and deep learning methods. We then leveraged advanced transformer-based models, including BERT, XLNet, and RoBERTa, optimizing their performance through careful hyperparameter tuning. The research methodology involves utilizing two Arabic news article datasets, AFND and ARABICFAKETWEETS datasets, categorized into fake and real subsets and applying comprehensive preprocessing techniques to the text data. Four hybrid deep learning models are presented: CNN-LSTM, RNN-CNN, RNN-LSTM, and Bi-GRU-Bi-LSTM. The Bi-GRU-Bi-LSTM model demonstrated superior performance regarding the F1 score, accuracy, and loss metrics. The precision, recall, F1 score, and accuracy of the hybrid Bi-GRU-Bi-LSTM model on the AFND Dataset are 0.97, 0.97, 0.98, and 0.98, and on the ARABICFAKETWEETS dataset are 0.98, 0.98, 0.99, and 0.99 respectively. The study’s primary conclusion is that when spotting fake news in Arabic, the Bi-GRU-Bi-LSTM model outperforms other models by a significant margin. It significantly aids the global fight against false information by setting the stage for future research to expand fake news detection to multiple languages.
Enhancing celery’s growth, production, quality, and nutritional status using tryptophan and glycine amino acids
Authors: El-Tanahy A. M. M. , Mahmoud Sami H. , Elwahed Mohamed S. A. Abd , Salama Dina M.
Published: November 2024

Finding a way to establish a sustainable cultivation system to produce celery as an important source of human being nutrition system due to its health and nutritional advantages is increasing by the day. Amino acids have a deep impact on plant metabolism; they improve mineral uptake and increase shoots and root growth, yield, chlorophyll biosynthesis, and photosynthesis rate as well as encouraging stimulation of several enzymes and coenzymes which lead to improved plant development and production besides quality. A two-year (2021/2022–2022/2023), trial was conducted to discuss two essential amino acids Glycine (GLY) and Tryptophan (TRP) effect on celery’s growth, production, photosynthetic pigments, vitamin (C), total phenols, total flavonoids, total antioxidant activity, total indoles, nutritional status, and amino acids contents. During the winter season, three levels of each amino acid (0, 50, and 75 mg/l) were sprayed in two doses after 30 days of cultivation and 15 days from the first foliar. Results showed that the best performance of amino acids on plants vegetative growth characteristics, photosynthetic pigments, biochemical constituents, yield, and amino acids content was conducted by using (GLY + TRP) mix followed by TRP then GLY, while the best level of foliar applied amino acids was 75 mg/l in concentration. The best results on celery’s vegetative growth, yield, chemical content, and amino acid content were recorded by using the (GLY + TRP) mix at the highest level of 75 mg/l in concentration.
Inter- and intra-examiner reliability of short-term measurement of heart rate variability on rest in patients hospitalized with COVID-19
Authors: Santos-de-Araújo Aldair Darlan , Oliveira Murilo Rezende , Pontes-Silva André , Rodrigues Laise Nunes , Costa Cyrene Piazera Silva , Marinho Renan Shida , de Sousa dos Santos Sigrid , Arena Ross , Phillips Shane A. , Bassi-Dibai Daniela , Borghi-Silva Audrey
Published: November 2024

Measures reflecting cardiac sympathovagal activity, particularly those associated with heart rate variability (HRV), are widely recognized and utilized in both scientific and clinical contexts. This study aimed to assess the inter- and intra-examiner reliability of short-term HRV parameters in patients hospitalized with coronavirus disease 2019 (COVID-19). A total of 103 patients (both sexes) diagnosed with COVID-19 were included in the study. HRV was analyzed using both linear and nonlinear methods. Reliability was evaluated through intraclass correlation coefficient (ICC2.1), minimum detectable change (MDC), standard error of measurement (SEM), and coefficient of variation (CV). According to Fleiss’ criteria, excellent reliability was demonstrated, with ICC values ranging from 0.970 to 0.999 for Examiner 1, and from 0.956 to 0.999, for Examiner 2. In the inter-examiner analysis, the ICCs of HRV parameters ranged from 0.972 to 0.999. SEM values for intra-examiner reliability for Examiner 1 ranged from 0.02 to 5.64, with MDC values from 0.05 to 15.64, and CV (%) from 0.28 to 8.04. For Examiner 2, SEM values ranged from 0.02 to 8.18, MDC values from 0.05 to 22.68, and CV (%) from 0.24 to 8.14. For inter-examiner reliability, SEM values ranged from 0.02 to 6.17, MDC from 0.06 to 17.11, and CV (%) from 0.34 to 9.81. Across all analyses, CVs for HRV parameters remained below 10%. Considering different time points and different examiners, short-term resting HRV measurements in patients hospitalized with COVID-19, as evaluated using a portable heart rate device, exhibit high reliability.
High-throughput Bronchus-on-a-Chip system for modeling the human bronchus
Authors: Mori Akina , Vermeer Marjolein , van den Broek Lenie J. , Heijmans Jeroen , Nicolas Arnaud , Bouwhuis Josse , Burton Todd , Matsumura Kazushi , Ohashi Kazuhiro , Ito Shigeaki , Kramer Bart
Published: November 2024

Airway inflammation, a protective response in the human body, can disrupt normal organ function when chronic, as seen in chronic obstructive pulmonary disease (COPD) and asthma. Chronic bronchitis induces goblet cell hyperplasia and metaplasia, obstructing airflow. Traditional animal testing is often replaced by in vitro three-dimensional cultures of human epithelial cells to assess chronic cell responses. However, these cells are cultured horizontally, differing from the tubular structure of the human airway and failing to accurately reproduce airway stenosis. To address this, we developed the Bronchus-on-a-Chip (BoC) system. The BoC uses a novel microfluidic design in a standard laboratory plate, embedding 62 chips in one plate. Human bronchial epithelial cells were cultured against a collagen extracellular matrix for up to 35 days. Characterization included barrier integrity assays, microscopy, and histological examination. Cells successfully cultured in a tubular structure, with the apical side air-lifted. Epithelial cells differentiated into basal, ciliated, and secretory cells, mimicking human bronchial epithelium. Upon exposure to inducers of goblet cell hyperplasia and metaplasia, the BoC system showed mucus hyperproduction, replicating chronic epithelial responses. This BoC system enhances in vitro testing for bronchial inflammation, providing a more human-relevant and high-throughput method.
Histidine containing dipeptides protect epithelial and endothelial cell barriers from methylglyoxal induced injury
Authors: Wetzel Charlotte , Gallenstein Nadia , Peters Verena , Fleming Thomas , Marinovic Iva , Bodenschatz Alea , Du Zhiwei , Küper Katharina , Dallanoce Clelia , Aldini Giancarlo , Schmoch Thomas , Brenner Thorsten , Weigand Markus Alexander , Zarogiannis Sotirios G. , Schmitt Claus Peter , Bartosova Maria
Published: November 2024

Integrity of epithelial and endothelial cell barriers is of critical importance for health, barrier disruption is a hallmark of numerous diseases, of which many are driven by carbonyl stressors such as methylglyoxal (MG). Carnosine and anserine exert some MG-quenching activity, but the impact of these and of other histidine containing dipeptides on cell barrier integrity has not been explored in detail. In human proximal tubular (HK-2) and umbilical vein endothelial (HUVEC) cells, exposure to 200 µM MG decreased transepithelial resistance (TER), i.e. increased ionic permeability and permeability for 4-, 10- and 70-kDa dextran, membrane zonula occludens (ZO-1) abundance was reduced, methylglyoxal 5-hydro-5-methylimidazolones (MG-H1) formation was increased. Carnosine, balenine (ß-ala-1methyl-histidine) and anserine (ß-ala-3-methyl-histidine) ameliorated MG-induced reduction of TER in both cell types. Incubation with histidine, 1-/3-methylhistidine, but not with ß-alanine alone, restored TER, although to a lower extent than the corresponding dipeptides. Carnosine and anserine normalized transport and membrane ZO-1 abundance. Aminoguanidine, a well-described MG-quencher, did not mitigate MG-induced loss of TER. Our results show that the effects of the dipeptides on epithelial and endothelial resistance and junction function depend on the methylation status of histidine and are not exclusively explained by their quenching activity.
Allometric fat mass index and alanine aminotransferase attenuate the associations of platelet parameters with lung cancer risk
Authors: Christakoudi Sofia , Tsilidis Konstantinos K. , Gunter Marc J. , Riboli Elio
Published: November 2024

We have previously shown that body mass index attenuates a positive association of platelet count (PLT) and inverse of mean platelet volume (MPV) with lung cancer risk in men. It is unclear whether fat mass, lean mass, or liver function tests (LFTs) show similar attenuations. Using bioelectrical impedance measurements (UK Biobank cohort) and multivariable Cox proportional hazards models, we examined the associations of allometric fat-mass index (AFI, fat mass adjusted for height), allometric lean-mass index (ALI, fat-free mass adjusted for height and fat mass), and LFTs with lung cancer risk and their multiplicative and additive interactions with platelet parameters. Based on 1573 lung cancer cases in men and 1473 in women with body composition measurements (1541 in men; 1428 in women with biomarker measurements), AFI in women, ALI in both sexes, alanine aminotransferase (ALT) and total bilirubin in men were inversely associated, while gamma-glutamyl transferase in men and alkaline phosphatase in both sexes were positively associated with lung cancer risk. Only AFI and ALT interacted inversely with PLT and positively with MPV in men. The attenuation of the associations of platelet parameters with lung cancer risk by high-AFI and high-ALT in men suggests that adiposity-related factors hinder lung-cancer-related platelet associations.
Stabilizing Ni catalysts in biogas reforming via in situ carbon deposit removal by CeO2 oxygen vacancies
Authors: Gang Yonggang , Zhao Zijiang , Long Yanhui , Li Xiaodong , Zhang Hao
Published: November 2024

Surface oxygen vacancies (Ov) in the catalyst facilitate an in situ consumption mechanism, effectively eliminating carbon deposits for biogas reforming.
RAFT solution polymerisation of bio-based γ-methyl-α-methylene-γ-butyrolactone monomer in DMSO and Cyrene
Authors: Harris Oliver J. , Larder Ryan R. , Jordan Beth , Prior Imogen , El-Khoury Rita , Sebakhy Khaled O. , Hatton Fiona L.
Published: November 2024

We report the RAFT solution polymerisation of bio-based monomer γ-methyl-α-methylene-γ-butyrolactone in DMSO and the more sustainable solvent Cyrene.
Recent developments in the photoredox catalyzed Minisci-type reactions under continuous flow
Authors: Pillitteri Serena , Van der Eycken Erik V. , Sharma Upendra K.
Published: November 2024

Recent developments in flow protocols for the Minisci reaction highlight its versatility and potential for industrial applications.
Controlled nucleation of ultrasmall MoO3 nanoparticles on defective graphene for enhanced ammonia efficiency
Authors: Bhardwaj Sakshi , Santra Sumon , Dey Ramendra Sundar
Published: November 2024

The controlled nucleation of MoO3 ultrasmall nanoparticles on defective graphene sheets leads to the achievement of a FE of 43.1%.
Deciphering the spectroscopic and thermodynamic aspects of binding of biologically important antioxidants with the alkali induced state of human serum albumin
Authors: Maheshwari Anjali , Kishore Nand
Published: November 2024

Protein–ligand interactions are crucial for developing and identifying novel therapeutic targets.
Energy transfer from the [WO6]6− group to Er3+ in Lu2WO6 and favorable optical thermometry with strong emission color variability
Authors: Xue Xuyan , Gong Changshuai , Yang Sihan , He Jian , Li Meiting , Wang Xuejiao
Published: November 2024

Non-contact optical temperature measurement has attracted intense attention in recent years due to its advantages of high speed and high safety.
Amorphous CoFePOx hollow nanocubes decorated with g-C3N4 quantum dots to achieve efficient electrocatalytic performance in the oxygen evolution reaction
Authors: Yuan Ke , Zhou Wei , Zhu Xiaoyan , Ou Weihua , Chen Minzhe , Zhu Chuheng , Chen Ningning , Zuo Haofeng , Wang Aocheng , Zhao Dengke , An Maozhong , Li Ligui
Published: November 2024

g-C3N4 quantum dots decorated on amorphous CoFePOx hollow nanocubes can effectively adjust the electronic structure of CoFePOx substrates and substantially improve the electrocatalytic activity of amorphous CoFePOx nanocubes for oxygen evolution reaction (OER).
Continuous versus Intermittent Blood Pressure Monitoring in Postpartum Preeclampsia with Severe Features
Authors: Woolcock Martinez Helen , Haghighi Noora , van Wingerden Anne-Sophie , Kirschner Michael , Booker Whitney A. , Bello Natalie A. , Petersen Nils , Miller Eliza C.
Published: November 2024

Objective In this study, we piloted the use of continuous 24-hour blood pressure (BP) monitoring in postpartum patients with preeclampsia with severe features.

Study Design We measured continuous BP for up to 24 hours using finger plethysmography. We also used an oscillometric device to measure brachial BP per usual clinical protocol (intermittent BP) during the same monitoring period. Using a paired t-test, we compared mean BP values assessed using intermittent and continuous methods, and using McNemar's test, we compared the proportion of patients with sustained severe-range BP using each BP measurement method.

Results A total of 25 patients were included in this study. There was no difference in mean systolic BP (SBP) and mean arterial pressure between intermittent and continuous BP measurements. Intermittently recorded mean diastolic BP (DBP) was significantly higher than continuously recorded DBP. Eleven participants (44%) had sustained SBP ≥160 mm Hg using continuous monitoring compared with two using intermittent monitoring (p = 0.003). Of these 11 participants, 3 (37%) also recorded sustained DBP ≥110 mm Hg using continuous monitoring compared with none using intermittent monitoring.

Conclusion Continuous BP monitoring is a feasible and reliable method for detecting sustained severe-range BP in postpartum patients receiving treatment for preeclampsia with severe features.

Key Points
Tunneling as a marker of quantum mechanics (Review article)
Authors: Gabovich Alexander M. , Kuznetsov Volodymyr I. , Voitenko Alexander I.
Published: November 2024

A short historical review of the development of tunneling concept in low-temperature condensed matter physics, physical electronics, nuclear physics, chemistry, and biology is given. It is shown how the preceding classical physics is related to the quantum mechanical tunneling phenomenon. The emphasis is placed on the common features of various tunneling manifestations in nature. The triumph of the Faraday–Maxwell–Einstein idea of the physical field has been demonstrated.
Escape rate in small Josephson junctions with the Coulomb blockade
Authors: Askerzade I. N.
Published: November 2024

In this study, we carried out the analysis of the escape rate in small Josephson junctions with Coulomb blockade of Cooper pairs. It was shown that escape rate in small junctions is determined by the energy ratio parameter κ=EJ/EC in thermal activation and macroscopic quantum tunneling regimes. In the thermal activation regime, temperature also increases the escape rate.
On a model of a Josephson junction with a single quantum channel featuring a “deformed” Andreev reflection coefficient
Authors: Sergeyev D. , Shunkeyev K. , Solovjov A. L.
Published: November 2024

This paper presents calculations of the current-voltage, dI/dV- and d2I/dV2-characteristics for a Josephson junction with a short one-dimensional channel, taking into account a “deformed” (anomalous) energy-dependent Andreev reflection function. Depending on the degree of deviation from the classical Andreev reflection coefficient, the “anomalous” functions are conditionally divided into weakly and strongly deformed coefficients. The excess Andreev current decrease is demonstrated with increasing anomaly factor due to the low probability of multiple Andreev reflections compared to the classical case. It has been shown that anomalous fractional (fractal) gap structures arise in the spectra, which require experimental verification. The analysis shows that on the spectrum of modified dynamic conductivity, when considering the anomalous function of Andreev reflections, the second Andreev feature becomes more pronounced as a minimum and the first feature manifests as a notable kink, which is absent in the classical dependencies for cases of high transparency obtained within the Averin–Bardas model. In the anomalous mode, the Andreev features appear as “dips” in the relatively high-energy region, which have also been detected in the Josephson junction spectra, indicating the possibility of generating high-frequency phonons.
First-principles insights into Ptn/ZnO(0001) catalyst: Regulation of metal-support interaction through surface polarity
Authors: Sun Yue-Tong , Zheng Ju-Fang , Wang Ya-Hao , Zhou Xiao-Shun , Wan Qiang
Published: November 2024

Polar surfaces are prevalent in metal oxides, the interactions between surface species with polar surfaces are different from those with non-polar surfaces, a thorough understanding of the interactions is key to regulate the performance of heterogeneous catalysts. In this work, we delve into the interaction of Ptn (n=1–4) with polar ZnO(0001)-Zn and ZnO(0001¯)-O, and the influence of the surface polarity on the electronic structures and reactivity of Ptn by using density functional theory calculations. The results suggest distinct differences in electronic structures of two exposed terminations, leading to different interactions with Ptn. The interaction between Ptn and two terminations not only stabilizes the surface and clusters through polar compensation, but also induces opposite charges on the cluster at two terminations. Remarkably, the Pearson correlation coefficient reveals the interdependency between the electronic states of Ptn and its performance in terms of small molecule adsorption/activation. These observations demonstrate the crucial role of surface polarity in regulating the electronic states and catalytic performance of active sites, and offer a possible design principle for supported catalysts.
Insights into reduction of CO2 to CO catalyzed by pyramidal-4Ni clusters supported on doped CeO2(111)
Authors: Qin Ruimin , Shen Shenyu , Li Boyang , Zhu Tingyi , Wu Tiantian , Ding Shujiang , Su Yaqiong
Published: November 2024

Converting CO2 into valuable chemicals has become a widely used research method for CO2 conversion. In this work, the catalytic performance of pyramidal-4Ni catalysts supported on rare earth metal-doped CeO2 toward CO2 reduction reaction (CO2RR) was investigated by using density-functional theory calculations. For rare earth metal-doped CeO2, 2Ce is substituted by 2 trivalent cations and at the same time one oxygen vacancy is created to make charge compensation. We investigated the oxygen vacancy nearest (VO,N) and next-nearest (VO,NN) to 4Ni, and found releasing CO and CO2 dissociation are the rate-determining steps, respectively, via the path of VO,N and VO,NN. Among the studied dopants (Ga, Sb, Lu, Gd, Pr, La, Bi), Gd is identified as the best dopant for catalyzing the reduction of CO2 at 823 K, with the turn-over frequency (TOF) of 104 times as large as that over 4Ni supported on pure CeO2. This exploration pro-vides theoretical support and guidance for the research and application of rare earth metaldoped CeO2-loaded Ni catalysts in the field of CO2 reduction.
GALADRIEL: A facility for advancing engineering science relevant to rep-rated high energy density physics and inertial fusion energy experiments
Authors: Collins G. W. , McGuffey C. , Jaris M. , Vollmer D. , Dautt-Silva A. , Linsenmayer E. , Keller A. , Ramirez J. C. , Sammuli B. , Margo M. , Manuel M. J.-E.
Published: November 2024

Many current and upcoming laser facilities used to study high-energy-density (HED) physics and inertial fusion energy (IFE) support operating at high rep-rates (HRRs) of ∼0.1–10 Hz, yet many diagnostics, target-fielding strategies, and data storage methods cannot support this pace of operation. Therefore, established experimental paradigms must change for the community to progress toward rep-rated operation. To this end, we introduce the General Atomics LAboratory for Developing Rep-rated Instrumentation and Experiments with Lasers, or GALADRIEL, to serve as a test bed for developing and benchmarking the engineering science advancements required for HRR experiments. GALADRIEL was constructed from the ground up around a commercial 1 TW (∼25 mJ in ∼25 fs at 800 nm) laser with diverse experimental applications in mind. Assembly of the basic framework of GALADRIEL concluded with commissioning shots generating ∼1–4 MeV electrons via laser-wakefield acceleration (LWFA) using a nitrogen gas jet. Subsequent LWFA experiments operated at 1 Hz, utilized instrument feedback for optimization, and stored all data in a custom-built NoSQL database system. From this database called MORIA, or the MOngodb Repository for Information Archiving, data are retrievable via individual files or en masse by query requests defined by the user. GALADRIEL focuses on outstanding questions in engineering science, including targetry, diagnostics, data handling, environmental and materials studies, analysis and machine learning algorithm development, and feedback control systems. GALADRIEL fills a niche presently missing in the US-based user-facility community by providing a flexible experimental platform to address problems in engineering science relevant to rep-rated HED and IFE experiments.
Microscopic mechanism of water-assisted diffusional phase transitions in inorganic metal halide perovskites
Authors: Liu Jialin , Hao Xiangming , van Huis Marijn A. , Fan Zhaochuan
Published: November 2024

The stability of perovskite materials is profoundly influenced by the presence of moisture in the surrounding environment. While it is well-established that water triggers and accelerates the black–yellow phase transition, leading to the degradation of the photovoltaic properties of perovskites, the underlying microscopic mechanism remains elusive. In this study, we employ classical molecular dynamics simulations to examine the role of water molecules in the yellow–black phase transition in a typical inorganic metal halide perovskite, CsPbI3. We have demonstrated, through interfacial energy calculations and classical nucleation theory, that the phase transition necessitates a crystal–amorphous–crystal two-step pathway rather than the conventional crystal–crystal mechanism. Simulations for CsPbI3 nanowires show that water molecules in the air can enter the amorphous interface between the black and yellow regions. The phase transition rate markedly increases with the influx of interfacial water molecules, which enhance ion diffusivity by reducing the diffusion barrier, thereby expediting the yellow–black phase transition in CsPbI3. We propose a general mechanism through which solvent molecules can greatly facilitate phase transitions that otherwise have prohibitively high transition energies.
Transfer learning for accurate description of atomic transport in Al–Cu melts
Authors: Khazieva E. O. , Chtchelkatchev N. M. , Ryltsev R. E.
Published: November 2024

Machine learning interatomic potentials (MLIPs) provide an optimal balance between accuracy and computational efficiency and allow studying problems that are hardly solvable by traditional methods. For metallic alloys, MLIPs are typically developed based on density functional theory with generalized gradient approximation (GGA) for the exchange–correlation functional. However, recent studies have shown that this standard protocol can be inaccurate for calculating the transport properties or phase diagrams of some metallic alloys. Thus, optimization of the choice of exchange–correlation functional and specific calculation parameters is needed. In this study, we address this issue for Al–Cu alloys, in which standard Perdew–Burke–Ernzerhof (PBE)-based MLIPs cannot accurately calculate the viscosity and melting temperatures at Cu-rich compositions. We have built MLIPs based on different exchange–correlation functionals, including meta-GGA, using a transfer learning strategy, which allows us to reduce the amount of training data by an order of magnitude compared to a standard approach. We show that r2SCAN- and PBEsol-based MLIPs provide much better accuracy in describing thermodynamic and transport properties of Al–Cu alloys. In particular, r2SCAN-based deep machine learning potential allows us to quantitatively reproduce the concentration dependence of dynamic viscosity. Our findings contribute to the development of MLIPs that provide quantum chemical accuracy, which is one of the most challenging problems in modern computational materials science.
A perturbation theory for plasmonic coupling of nanocavities
Authors: Xue Xiaotian , Fan Yihang , Wang Weipeng , Yang Fei , Fu Wangyang , Ling Yunhan , Shi Ji , Zhang Zhengjun
Published: November 2024

Plasmonic coupling among nanocavities creates a significant collective response of near-field enhancement, leading to numerous applications such as extraordinary optical transmittance, enhanced spectroscopy, energy harvesting, photo-enhanced catalysis, meta-lens, etc. We report here a perturbation theory based on the two-body interaction potential to clarify the plasmonic coupling between/among nanocavities. With this theory, we demonstrated that one can calculate the near-field distribution of a cluster of nanocavities and that the results are in agreement with simulations by the finite element method and those measured by a scanning near-field optical microscope. The perturbation theory offers an effective way in dealing with the plasmonic coupling behavior of nanocavities.
Simplified and flexible coils for stellarators using single-stage optimization
Authors: Jorge R. , Giuliani A. , Loizu J.
Published: November 2024

Single-stage optimization, also known as combined plasma-coil algorithms or direct coil optimization, has recently emerged as a possible method to expedite the design of stellarator devices by including, in a single step, confinement, stability, and engineering constraints. In this work, we show how such frameworks allow us to find new designs in a streamlined manner, yielding a broad range of new configurations. Examples are shown for stellarators with a small number of coils and quasisymmetric stellarators with only one to three coils per half field-period, with external trim coils, helical coils, and a single set of coils generating both a quasi-axisymmetric and a quasi-helical equilibrium.
Reparameterization of the mW model to accurately predict the experimental phase diagram of methane hydrate
Authors: Jin Dongliang , Zhong Jing
Published: November 2024

Due to their high computational efficiency, the coarse-grained water models are of particular importance for practical molecular simulations of gas hydrates. In these models, the mW model is successfully used to study many thermodynamics and dynamics of methane hydrate. Yet, despite several decades of intense research, the mW model is still found to overestimate the melting temperature of methane hydrate. We here employ the minimum mean squared error estimation to revisit the key parameter of the mW model, which determines the strength of the tetrahedral angle of the water system. Relying on the free energy calculations, we first estimate the chemical potentials of water in the liquid phase for temperatures at which methane hydrate forms. We then turn to the mean squared error to describe the chemical potential deviation between the mW model and the TIP4P/ice model (the latter could reproduce the experimental phase diagram of methane hydrate). By minimizing the mean squared error, we finally have an optimized parameter for the mW model. In this part, we also discuss the pressure effect on such reparameterization procedure. Moreover, relying on the direct coexistence method, the melting temperature determined using the reparameterized mW model is found to be consistent with the experimental data. This strategy provides a means to improve the coarse-grained model to match the experimental observations for temperatures in the range of interest.
Conjugate direct resistance heating of metallic plates. multiplicities and stability
Authors: Krikkis Rizos N.
Published: November 2024

A numerical bifurcation analysis is presented for an industrial application where direct resistance heating through a DC is applied to a flat metallic plate, which is cooled by a turbulent boundary layer and radiation. The process is modeled with a conjugate heat transfer between the plate and the cooling air steam. The convective part of the heat transfer mechanism is formulated in the framework of an integral approach, considering a turbulent core based on power law velocity and temperature profiles and a thin laminar sublayer thermally coupled with axial conduction along the plate. The analysis reveals that the problem admits two solutions: one stable and one unstable, separated by a limit point. The existence of multiple solutions is a consequence of the nonlinear electric resistivity–temperature relationship, allowing thermal equilibrium between heat generation and heat dissipation in multiple points. The application of realistic boundary conditions at the wall–fluid interface shows that the thermal to the hydrodynamic boundary layer thicknesses ratio along the plate is no longer close to the value of 1.25, as it is the case with a constant wall temperature. Instead, significant deviations occur due to the thermal coupling between the wall and the cooling fluid. The multiplicity structure and, consequently, the limit points depend on the plate Reynolds number and on the conduction–convection parameter. The locus of the limit points defines an instability threshold beyond which any excess applied current will trigger a thermal runaway phenomenon. This is also an equivalent of the maximum current carrying capacity of the plate.
Investigation of the leakage mechanism in solar-blind AlGaN p-i-n photodetector at high reverse bias
Authors: Sun Zhaolan , Yang Jing , Zhao Degang , Liu Zongshun , Duan Lihong , Liang Feng , Chen Ping , Liu Bing , Zheng Fu , Liu Xuefeng
Published: November 2024

The leakage mechanism of solar-blind AlGaN p-i-n photodetectors has been investigated. By studying the temperature-dependent I–V curves, we determined that Poole–Frenkel emission is the main source of the leakage current, and the corresponding trap energy level is 0.61 eV. Cathodoluminescence measurement demonstrates that the leakage current of the device may be related to the deep-level traps in the p-AlGaN layer. An analysis of deep-level transient spectroscopy testing results for p-AlGaN suggests that nitrogen vacancies formed during the epitaxial growth of high Al-content p-AlGaN act as electron traps. The trap potential energy decreases at high reverse bias voltage, making trapped electrons easier to escape, which increases the leakage current.
Nonlinear saturation of the ion flow driven ion sound instability in a finite length plasma
Authors: Xu Liang , Chen Jian , Sun Haomin , Tan Haiyun , Wu Xuemei
Published: November 2024

The saturation mechanism and nonlinear evolution of the ion sound instability driven by the subsonic ion flow in a finite length plasma are studied by a one-dimensional hybrid model considering kinetic ions and Boltzmann electrons. Three regimes of the instability nonlinear behavior are identified as a function of the frequency of the ion-neutral charge exchange (CX) collision fcoll. In the first (collisionless-alike) regime when the CX frequency is low, the instability is saturated by ions trapping in wave potentials leading to the formation of phase space vortexes (PSVs). One of the PSVs subsequently expands and becomes system long in the steady state. The transition to the second (medium) regime occurs when fcoll≳vp/d, where vp is the PSV expansion velocity and d is the system length. In the second regime, CX collisions convert fraction of beam ions into slow ions that can be trapped in potentials of small scale ion sound eigenmodes fluctuations. The trapping of slow ions results in the formation of a chain of small scale PSVs and the disruption of the establishment of the single system long PSV. In the third (collision-dominated) regime when fcoll≳γ (γ is the instability growth rate), CX collisions transform all beam ions into slow ions and the instability is thereby eliminated.
Comparing parameterized and self-consistent approaches to ab initio cavity quantum electrodynamics for electronic strong coupling
Authors: Manderna Ruby , Vu Nam , Foley Jonathan J.
Published: November 2024

Molecules under strong or ultra-strong light–matter coupling present an intriguing route to modify chemical structure, properties, and reactivity. A rigorous theoretical treatment of such systems requires handling matter and photon degrees of freedom on an equal quantum mechanical footing. In the regime of molecular electronic strong or ultra-strong coupling to one or a few molecules, it is desirable to treat the molecular electronic degrees of freedom using the tools of ab initio quantum chemistry, yielding an approach referred to as ab initio cavity quantum electrodynamics (ai-QED), where the photon degrees of freedom are treated at the level of cavity QED. We analyze two complementary approaches to ai-QED: (1) a parameterized ai-QED, a two-step approach where the matter degrees of freedom are computed using existing electronic structure theories, enabling the construction of rigorous ai-QED Hamiltonians in a basis of many-electron eigenstates, and (2) self-consistent ai-QED, a one-step approach where electronic structure methods are generalized to include coupling between electronic and photon degrees of freedom. Although these approaches are equivalent in their exact limits, we identify a disparity between the projection of the two-body dipole self-energy operator that appears in the parameterized approach and its exact counterpart in the self-consistent approach. We provide a theoretical argument that this disparity resolves only under the limit of a complete orbital basis and a complete many-electron basis for the projection. We present numerical results highlighting this disparity and its resolution in a particularly simple molecular system of helium hydride cation, where it is possible to approach these two complete basis limits simultaneously. In this same helium hydride system, we examine and compare the practical issue of the computational cost required to converge each approach toward the complete orbital and many-electron bases limit. Finally, we assess the aspect of photonic convergence for polar and charged species, finding comparable behavior between parameterized and self-consistent approaches.
Flow reconstruction with uncertainty quantification from noisy measurements based on Bayesian physics-informed neural networks
Authors: Liu Hailong , Wang Zhi , Deng Rui , Wang Shipeng , Meng Xuhui , Xu Chao , Cai Shengze
Published: November 2024

Flow reconstruction based on limited measurement data, which can be considered as a state estimation problem, constitutes a fundamental task within the realm of fluid mechanics. In recent years, the physics-informed neural networks (PINNs) have been proposed to achieve flow field reconstruction by integrating the measurements with governing equations during network training. However, the performance is compromised by the presence of high-level data noise, and the uncertainty of the reconstructed flow fields remains unattainable. In this paper, we first perform a systematic study to investigate the impact of data noise on the reconstruction result of PINNs. Subsequently, we present strategies of early stopping and loss regularization, which can suppress the overfitting issue to some extent. Ensemble learning is also employed to quantify the uncertainty of the results from vanilla PINNs. In addition, we propose to use a Bayesian framework of PINNs (BPINNs) for flow field reconstruction, which incorporates the Bayesian neural network with PINNs. It is demonstrated that BPINNs are capable of reconstructing the velocity and pressure fields from sparse and noisy velocity measurements, while providing comprehensive uncertainty quantification of the flow fields simultaneously. Compared to the vanilla PINNs, BPINNs are more accurate and robust when there is a high level of data noise. We conduct experiments on two-dimensional cavity flow and the flow past a cylinder to validate the effectiveness of the proposed methods throughout the paper.
Lifetime mapping using femtosecond time-resolved photoemission electron microscopy
Authors: Koo Norman Tze Wei , Woo Kyung Chul , Lim Justin Wei Xiang , Loh Zhi-Heng
Published: November 2024

Time-resolved photoemission electron microscopy (PEEM) has established itself as a versatile experimental technique to unravel the ultrafast electron dynamics of materials with nanometer-scale resolution. However, the approach of performing PEEM-based, pixel-by-pixel lifetime mapping has not been reported thus far. Herein, we describe in detail the data pre-processing procedure and an algorithm to perform time-trace fittings of each pixel. We impose an energy cutoff for each pixel prior to spectral integration to enhance the robustness of our approach. With the energy cutoff, the energy-integrated time traces show improved statistics and lower fitting errors, thus resulting in a more accurate determination of the fit parameters, e.g., decay time constants. Our work allows us to reliably construct PEEM-based lifetime maps, which potentially shed light on the effects of local microenvironment on the ultrafast processes of the material and allow spatial distributions of lifetimes to be correlated with observables obtained from complementary microscopic techniques, hence enabling a more comprehensive characterization of the material.
Molten salt assisted synthesis of Si/C nanocomposite derived from palygorskite and sodium alginate for electrochemical lithium storage
Authors: Zhang Yan , Tian Jibin , Deng Jiangwei , Zhou Xiaozhong
Published: November 2024

Silicon/carbon (Si/C) nanocomposites are considered as one of the most promising anode materials for lithium-ion batteries due to their high capacity and suitable lithiation potential. However, the complex and time-consuming preparation processes of silicon-based nanocomposites and the unexpected silicon carbide generated during high treatment make it difficult to achieve high-performance Si/C nanocomposites for practical applications. Herein, a silicon/carbon nanocomposite is successfully prepared through a facile and eco-friendly molten salt assisted precarbonization–reduction method using palygorskite (PAL) and sodium alginate as raw materials. Based on physical characterizations, it is demonstrated that the sodium alginate plays a key role in the successful preparation of Si/C nanocomposite, which not only boosts uniform embedding of PAL nanoparticles in the carbon matrix but also releases molten sodium salt to suppress the formation of unexpected SiC. When used as an alternative anode material for lithium-ion battery applications, the as-obtained Si/C composite delivers a high reversible specific capacity of 1362.7 mA h g−1 with an initial Coulombic efficiency of 70.3% at a current density of 200 mA g−1 and excellent long-term cycling stability. The findings here provide a facile and eco-friendly molten salt assisted precarbonization–reduction method for high-performance silicon/carbon anode materials.
Towards a generalized droplet fragmentation model
Authors: Niranjan Pankaj , Bodi Kowsik , Gadgil Hrishikesh
Published: November 2024

Modeling the aerodynamic breakup of a droplet has been of interest as this process is fundamental in determining the droplet statistics in many spray applications. Toward these efforts, we select a recent model proposed by Jackiw and Ashgriz [“On aerodynamic droplet breakup,” J. Fluid Mech. 913, A33 (2021)] and attempt to enhance its suitability by proposing necessary modifications. In order to overcome the limitations of the original model, experiments are conducted systematically using the falling droplet method with liquids over a wide range of viscosities. Numerical simulations are also performed to second the experimental data. We observe that the droplet's passage through the jet shear layer delays the overall process by an amount equivalent to its residence time in the shear layer. Even though the initial deformation phase is relatively insensitive to the liquid viscosity, the final rupture time of the droplet and the child droplet statistics are found to be dependent on viscosity. These effects are quantified, and certain viscosity-dependent phenomena like viscous stretching are reported for further improvements in the model. In general, we show that the proposed modifications make the model more generic and comprehensive, improving its performance across a wide range of experimental conditions.
Shock driven bubble collapse near tissue like material for drug delivery processes
Authors: Wang Wanli , Lunkov Aleksandr , Adami Stefan , Adams Nikolaus A.
Published: November 2024

The paper demonstrates the phenomenology of shock-driven air bubble and triple-layer microbubble collapse near tissue-like gelatin by direct numerical simulation. We validate the numerical method by comparison with experimental data for water jet generated by shock-driven bubble collapse near a gelatin interface. Coupled dynamics of bubble collapse and gelatin deformation is revealed during the early stages of the process. As the shock wave overpressure decreases, the coupling effect becomes more pronounced. The phenomenology of agent delivery initiated by shock-driven triple-layer microbubble collapse is presented. The results show that increasing the shock overpressure or reducing the agent layer thickness significantly enhances delivery efficiency, with the attached triple-layer microbubble exhibiting the highest efficiency. The results show how process parameters settings in shock-driven multi-material microcapsule collapse can control agent delivery processes in biomedical therapies.
Wake interference effects for two surface-mounted cubes in tandem
Authors: da Silva Barbara L. , Sumner David , Bergstrom Donald J.
Published: November 2024

Interference effects on the mean flow field, aerodynamic forces, and vortex shedding in the wakes of two cubes in tandem have been experimentally investigated, considering different boundary layer thicknesses of δ/D=0.8 and 1.3. The cubes had center-to-center longitudinal spacing ratios of L/D=1.5 to 5 and were exposed to an incoming flow with a Reynolds number of Re =7.5×104–9×104 based on the cubes' width D and the freestream velocity. For the thin boundary layer, the flow showed an intermittent regime with two Strouhal numbers for L/D<2.25, a co-shedding regime with synchronized shedding for L/D>2.25, and evidence of a cavity-locked regime around L/D=2.75. The intermittent regime featured flow reattachment but was not bistable, corresponding instead to unsynchronized shedding from both the upstream and downstream cubes. The mean drag force, normal force, and bending moment coefficients were examined across the regimes as functions of L/D and δ/D, showing greater variation for the downstream cube. Particle image velocimetry measurements revealed that the probability of reattachment on the downstream cube decreased, a second horseshoe vortex formed in the gap, and flow separated from the downstream cube's leading edges for high L/D. When increasing δ/D, vortex shedding from the upstream cube was delayed, leading to a high Strouhal number single-wake regime for L/D<2.5. The shorter formation region caused fluid to enter the gap, giving higher drag force coefficients for the downstream cube for small L/D, while the decreased probability of reattachment on the top of the cube led to a small increase in its normal force coefficient.
Effect of 20 MeV proton irradiation on the electrical properties of NiOx/β-Ga2O3 p–n diodes
Authors: Feng Yahui , Guo Hongxia , Ma Wuying , Ouyang Xiaoping , Zhang Jinxin , Bai Ruxue , Zhang Fengqi , Wang Zhongming , Ma Xiaohua , Hao Yue
Published: November 2024

In this article, the impact of 20 MeV proton irradiation on NiOx/β-Ga2O3 p–n diodes has been investigated. After 20 MeV proton irradiation with a fluence of 2 × 1012 p/cm2, the forward current density (JF) decreased by 44.1% from 93.0 to 52.0 A/cm2, and the turn-on voltage (Von) increased from 1.55 to 1.68 V based on current–voltage (I–V) measurements. Moreover, the capacitance–voltage (C–V) measurements indicated that the net carrier concentration in the β-Ga2O3 lightly doped drift region was reduced from 1.95 × 1016 to 1.86 × 1016 cm−3 after proton irradiation. The effect of proton irradiation on NiOx/β-Ga2O3 interface trap states was also acquired utilizing the frequency-dependent conductance technique. The results indicated that the time constant increased from 0.04–0.15 to 0.13–0.23 μs after proton irradiation. Meanwhile, it was found that the density of interface trap states increases from 7.49 × 1010–1.27 × 1010 to 7.23 × 1011–1.70 × 1012 cm−2 eV−1 with an increase in trap activation energy from 0.080–0.111 to 0.088–0.121 eV after proton irradiation. This work provides an important reference for further improving the performance of NiOx/β-Ga2O3 p–n diodes through the design of subsequent anti-radiation hardening.
Search amps up for signatures of cosmic particles in ancient minerals
Authors: Feder Toni
Published: November 2024

Advances in imaging and data handling open new possibilities.