bluuebunny/crossref_metadata_2025 huggingface dataset:
Ensemble-Based Machine Learning Algorithms Combined with Near Miss Method for Software Bug Prediction
Authors: Khleel Nasraldeen Alnor Adam , Nehéz Károly , Fadulalla Montaser , Hisaen Ahmed
Published: January 2025

Software bug prediction (SBP) involves identifying or categorizing software modules likely to contain defects, utilizing underlying system properties such as software metrics. SBP plays a crucial role in enhancing software project quality and mitigating maintenance risks. Numerous machine learning (ML) algorithms have been developed to predict software bugs. Class imbalance poses a significant challenge for these algorithms, significantly impeding their effectiveness and resulting in imbalanced false-positive and false-negative outcomes. However, limited research has been conducted to specifically tackle the issue of class imbalance in the context of SBP. This study investigates the prediction performance of a homogeneous ensemble: Bagging, boosting, and voting classifiers (VC) methods combined with the under-sampling methods to address the class imbalance problem and improve the accuracy of SBP. Two ensembles are classified as bagging ensembles: decision tree (DT) and random forest (RF); two ensembles are classified as boosting ensembles: AdaBoost (AB) and gradient boosting (GB), while the DT, RF, K-Nearest Neighbours (K-NN), and support vector machine (SVM) are considered as VC. To establish the effectiveness of the proposed models, the experiments were conducted on the available benchmark datasets, which comprise five public datasets based on both class and file-level metrics. We compared and evaluated the performance of the proposed models according to several performance measures, namely accuracy, precision, recall, f-measure, Matthew’s correlation coefficient (MCC), and the area under the receiver operating characteristic curve (AUROC). The experimental findings demonstrated that the proposed models exhibit superior efficiency in predicting software bugs on balanced datasets compared to the original datasets, with an improvement of up to 11% accuracy for the class-level metrics and 10% for the file-level metrics. The results indicate that the use of data sampling techniques had a positive impact on the prediction accuracy of the presented models. We compared our proposed method with existing SBP methods based on several standard performance measures. The comparison outcomes revealed a significant superiority of our method over the prevailing state-of-the-art SBP methods across most datasets.
Modified water balance model for groundwater recharge estimations using cloud integration
Authors: Das Arup Kumar , Gupta Saurabh Kumar , Singh Suraj Kumar , Rawat Pradeep Kumar , Kanga Shruti
Published: January 2025

Groundwater recharge is an essential element of enhancing global water governance. This is conspicuous over areas like West Bengal, India, which face natural and manmade water resource challenges. This particular study aims at improving the estimation of groundwater recharge using the Modified Water Balance Model (MWBM), which has been integrated with Google Earth Engine (GEE) and high-resolution remote sensing data here in application for groundwater. The method used consists of MODIS land surface temperature and CHIRPS precipitation data efficiently maps groundwater recharge estimation for various districts of West Bengal. The MWBM utilizes the geospatial analytic capabilities of GEE and above calculations in MWBM in creating recharge estimations that are geographically referenced. The majority of the results showed significant differences in the spatial recharge characteristics of the aquifers across the study region. High recharge was found in Alipurduar and Jalpaiguri district because of the high rainfall but low and constant recharge potential in Bankura and Purba Bardhaman districts due to less permeable rock layers. Within MWBM, improvements in groundwater management include the use of remote sensing techniques as well as modernization of computational processes to enhance recharge estimates. The present study not only aims at improving the accuracy of recharge estimation methods but also suggests a workable approach in the context of water resource management plans.
Three-dimensional stability of natural convection flows in inclined square enclosures
Authors: Shen Henry K , Hussam Wisam K. , Sheard Gregory J.
Published: January 2025

The three-dimensional stability of two-dimensional natural convection flows in a heated, square enclosure inclined to the horizontal is investigated numerically. First, the computational procedure is validated by comparison of base flow solutions to results reported in literature across a range of inclinations. A bi-global linear stability analysis is then conducted to investigate the stability of these two-dimensional base flows to infinitesimal three-dimensional perturbations, and the effect that buoyancy forces (defined by a buoyancy number

$R_N$

) and enclosure inclination

$\theta$

have on these stability characteristics. The flow is first observed to become three-dimensionally unstable at buoyancy number

$R_N = 213.8$

when

$\theta$

is

$180^\circ$

; this increases to

$R_N = 2.54 \times 10^4$

at inclination

$\theta =58^\circ$

. It is found that the two-dimensional base flow is more unstable to three-dimensional perturbations with the critical

$R_N$

corresponding to three-dimensional instability being significantly lower than its two-dimensional counterpart across all considered inclinations except

$83^\circ \leq \theta \leq 88^\circ$

, where the most unstable mode is a two-dimensional oscillatory mode that develops in the boundary layers along the conducting walls. Eight different leading three-dimensional instability modes are identified, with inclinations

$58^\circ \leq \theta < 88^\circ$

transitioning through an oscillatory mode, and inclinations

$88^\circ \leq \theta \leq 180^\circ$

transitioning through a stationary mode. The characteristics of the primary instability modes corresponding to inclinations

$88^\circ \leq \theta \leq 179^\circ$

indicate the presence of a Taylor–Görtler instability.
Heroes and Villains?
Authors: Thakkar Jonny
Published: January 2025

Eich’s book is a tour de force. It takes us through six episodes in which the history of political theory and the history of political economy intersect through the topic of money. From Aristotle to Locke and Fichte and then through to Marx and Keynes before a final episode costarring Hayek, Rawls, Habermas, and Walzer, we are treated to a fascinating set of reflections on what money is and should be, each articulated in the face of a particular historical crisis. This approach gives us a new way of thinking about what is salient in the history of political thought, but it also helps us think about the present. Eich hopes to move us beyond narrow debates over the depoliticization of money by insisting that money is always already political even when it announces itself as antipolitical, so that the real question is which conception of political life—which values but also which underlying social theory—we want to be embedded in monetary institutions. In explicitly tethering his patient, detailed historical scholarship to the broader goal of stimulating and invigorating reflection on one of the central issues of our own day, Eich tries to overcome the divide between historical work and contemporary debate.
Analogy and Image in E. L. Mascall
Authors: Jankowski Jarek Macachor
Published: January 2025

E. L. Mascall devoted much of his early scholarly career to developing accounts of analogy and natural theology grounded in the study both of Thomas Aquinas and in his Thomist successors. This essay examines Mascall’s account of analogy in relation to other views on analogy in his day, finding that in the 1950s, ‘image’ becomes at least as important a category for Mascall as ‘analogy’. Even while beginning from Thomist metaphysical standpoints and motivated by Thomist considerations, Mascall develops an account of thinking and speaking about God that diverges from his Thomist contemporaries, resembling more the thought of his ‘para-Thomist’ friend and colleague, Austin Farrer.
God Did Not Choose to Save the World by Talk: E.L. Mascall on the Incarnation and Its Consequences
Authors: Smith Christopher Matthew
Published: January 2025

Given as the Pusey House Recollections Lecture 2023.
Answering Liberal Protestantism: Eric Mascall and Karl Barth
Authors: Michielin Maico
Published: January 2025

Eric Mascall and Karl Barth shared a common concern with the influence of liberal Protestantism on their churches in England and Germany. They agreed this problem was best addressed through the lens of natural theology. Yet, while for Mascall a Thomistically informed understanding of natural theology was the best way to counteract liberal Protestantism’s influence on the Church, for Barth, natural theology was to blame for the Church’s confusion. The concern this paper raises was Barth’s sharp delineation between human reason and divine revelation in the end, complicit with the ontological duality of modernity that was the basis of the liberal Protestantism he was rejecting? By dealing with modernity on its own terms, Barth undermined the capacity of the Church’s ministry of Word and Sacrament to be effective agents of personal transformation. Whereas Mascall’s realistic ontology not only repudiates the idealist foundations of liberal Protestantism but also offers the Church the necessary ontology foundation for understanding its ministry of Word and Sacrament as effective embodiments of God’s transforming grace.
Soil Residual Activity of Tetflupyrolimet and the Influence of Soil Moisture and Flood Timeliness on Barnyardgrass Efficacy
Authors: Castner Mason C. , Norsworthy Jason K. , Roberts Trenton L. , Faske Travis R. , Butts Thomas R. , Bateman Nick R.
Published: January 2025

Tetflupyrolimet is the first herbicide with a novel site of action to be commercialized for use in agronomic crops in three decades. Direct-seed rice field experiments were conducted at research facilities near Stuttgart (silt loam), AR, and Keiser (clay), AR, to evaluate tetflupyrolimet as a preemergence herbicide versus commercial standards. Greenhouse experiments determined the influence of soil moisture on pre- and postemergence (POST) barnyardgrass control with tetflupyrolimet and clomazone, and the impact of a delayed flood on efficacy when POST-applied. For the field experiments, clomazone, tetflupyrolimet, and quinclorac were applied individually PRE at 336 and 560, 134 and 224, and 336 and 560 g ai ha-1, respectively, on a silt loam and clay soil, along with clomazone plus tetflupyrolimet and clomazone plus quinclorac at the same rates. The soil moisture experiment included a single PRE and POST application of clomazone at 336 g ai ha-1, tetflupyrolimet at 134 g ai ha-1, and a mixture at the respective rates, on a silt loam soil at 50, 75, and 100% of field capacity. For the flood timing experiment, tetflupyrolimet was applied to 2- to 3-leaf barnyardgrass at 134 g ai ha-1, and a flood was established at 4 hr after treatment (HAT) and 5 and 10 d after treatment (DAT). Barnyardgrass control with a tetflupyrolimet and clomazone mixture was comparable to clomazone plus quinclorac when averaged over all evaluations on silt loam and clay texture soils (≥91%). Soil moisture interacted with herbicide treatments for PRE and POST barnyardgrass efficacy when averaged over DAT, with tetflupyrolimet plus clomazone generally providing the greatest and most consistent control across regimes. Flooding barnyardgrass at 4 HAT provided superior control to later flood timings. Tetflupyrolimet is an effective residual barnyardgrass herbicide, and the addition of clomazone will aid in providing consistent control across varying soil moisture conditions.
Contributions of distractor dwelling, skipping, and revisiting to age differences in visual search
Authors: Wiegand Iris , van Pouderoijen Mariska , Oosterman Joukje M. , Deckers Kay , Horstmann Gernot
Published: January 2025

Visual search becomes slower with aging, particularly when targets are difficult to discriminate from distractors. Multiple distractor rejection processes may contribute independently to slower search times: dwelling on, skipping of, and revisiting of distractors, measurable by eye-tracking. The present study investigated how age affects each of the distractor rejection processes, and how these contribute to the final search times in difficult (inefficient) visual search. In a sample of Dutch healthy adults (19–85 years), we measured reaction times and eye-movements during a target present/absent visual search task, with varying target-distractor similarity and visual set size. We found that older age was associated with longer dwelling and more revisiting of distractors, while skipping was unaffected by age. This suggests that increased processing time and reduced visuo-spatial memory for visited distractor locations contribute to age-related decline in visual search. Furthermore, independently of age, dwelling and revisiting contributed stronger to search times than skipping of distractors. In conclusion, under conditions of poor guidance, dwelling and revisiting have a major contribution to search times and age-related slowing in difficult visual search, while skipping is largely negligible.
Mind the leaf anatomy while taking ground truth with portable chlorophyll meters
Authors: Lhotáková Zuzana , Neuwirthová Eva , Potůčková Markéta , Červená Lucie , Hunt Lena , Kupková Lucie , Lukeš Petr , Campbell Petya , Albrechtová Jana
Published: January 2025

A wide range of portable chlorophyll meters are increasingly being used to measure leaf chlorophyll content as an indicator of plant performance, providing reference data for remote sensing studies. We tested the effect of leaf anatomy on the relationship between optical assessments of chlorophyll (Chl) against biochemically determined Chl content as a reference. Optical Chl assessments included measurements taken by four chlorophyll meters: three transmittance-based (SPAD-502, Dualex-4 Scientific, and MultispeQ 2.0), one fluorescence-based (CCM-300), and vegetation indices calculated from the 400–2500 nm leaf reflectance acquired using an ASD FieldSpec and a contact plant probe. Three leaf types with different anatomy were included: dorsiventral laminar leaves, grass leaves, and needles. On laminar leaves, all instruments performed well for chlorophyll content estimation (R2 > 0.80, nRMSE < 15%), regardless of the variation in their specific internal structure (mesomorphic, scleromorphic, or scleromorphic with hypodermis), similarly to the performance of four reflectance indices (R2 > 0.90, nRMSE < 16%). For grasses, the model to predict chlorophyll content across multiple species had low performance with CCM-300 (R2 = 0.45, nRMSE = 11%) and failed for SPAD. For Norway spruce needles, the relation of CCM-300 values to chlorophyll content was also weak (R2 = 0.45, nRMSE = 11%). To improve the accuracy of data used for remote sensing algorithm development, we recommend calibration of chlorophyll meter measurements with biochemical assessments, especially for species with anatomy other than laminar dicot leaves. The take-home message is that portable chlorophyll meters perform well for laminar leaves and grasses with wider leaves, however, their accuracy is limited for conifer needles and narrow grass leaves. Species-specific calibrations are necessary to account for anatomical variations, and adjustments in sampling protocols may be required to improve measurement reliability.
Psychometric study of the Maslach Burnout Inventory-Student Survey on Thai university students
Authors: López-Gómez Ernesto , González-Fernández Raúl , Khampirat Buratin
Published: January 2025

The Maslach Burnout Inventory-Student Survey (MBI-SS) is a widely used instrument to assess burnout levels, which provides valuable insight into their psychological well-being. Accurate measurement of burnout is crucial for developing interventions aimed at reducing stress and promoting mental health among students. This study aims to validate the MBI-SS when applied among Thai university students and to examine whether the psychometric properties of the scale are consistent with the original conceptual framework. A total of 413 undergraduate students from Thailand participated in the study, with 57.63% females and 42.37% males, and a mean age 21.75 years (SD = 2.40). The MBI-SS was translated into Thai by following rigorous procedures to maintain accuracy and cultural relevance. The factorial structure of the MBI-SS Thai version was evaluated using confirmatory factor analysis (CFA) for both a three-factor model and second-order factor model. The Thai version of the MBI-SS demonstrated a three-dimensional structure consistent with the original inventory, with excellent model fit indices. All item factor loadings exceeded the recommended threshold, and the instrument showed high internal consistency, establishing it a valuable tool for future research and practical application in educational settings aimed at addressing and reducing student burnout.
Compound coastal flooding in San Francisco Bay under climate change
Authors: Wang Zhenqiang , Leung Meredith , Mukhopadhyay Sudarshana , Sunkara Sai Veena , Steinschneider Scott , Herman Jonathan , Abellera Marriah , Kucharski John , Ruggiero Peter
Published: January 2025

The risk of compound coastal flooding in the San Francisco Bay Area is increasing due to climate change yet remains relatively underexplored. Using a novel hybrid statistical-dynamical downscaling approach, this study investigates the impacts of climate change induced sea-level rise and higher river discharge on the magnitude and frequency of flooding events as well as the relative importance of various forcing drivers to compound flooding within the Bay. Results reveal that rare occurrences of flooding under the present-day climate are projected to occur once every few hundred years under climate change with relatively low sea-level rise (0.5 m) but would become annual events under climate change with high sea-level rise (1.0 to 1.5 m). Results also show that extreme water levels that are presently dominated by tides will be dominated by sea-level rise in most locations of the Bay in the future. The dominance of river discharge to the non-tidal and non-sea-level rise driven water level signal in the North Bay is expected to extend ~15 km further seaward under extreme climate change. These findings are critical for informing climate adaptation and coastal resilience planning in San Francisco Bay.
Selective laser processing of particle accelerator beam screen surfaces for electron cloud mitigation
Authors: Bez Elena , Portilla Ana Karen Reascos , Petit Valentine , Paraschou Konstantinos , Mether Lotta , Brunner Kristóf , Krkotić Patrick , Askar Yasemin , Calatroni Sergio , Taborelli Mauro , Himmerlich Marcel
Published: January 2025

The material properties of laser-treated LHC beam screens with low SEY are examined to validate compatibility with the operation conditions of particle accelerators.
A novel micelleplex for tumour-targeted delivery of CRISPR-Cas9 against KRAS-mutated lung cancer
Authors: Chen Siyu , Triki Mariem , Pinto Carneiro Simone , Merkel Olivia Monika
Published: January 2025

CRISPR-Cas9 has emerged as a highly effective and customizable genome editing tool, holding significant promise for the treatment of KRAS mutations in lung cancer.
Mechanistic study of the adsorption capabilities of heavy metals on the surface of ferrihydrite: batch sorption, modeling, and density functional theory
Authors: He Bihong , Zhang Wentao , Diao Yanan , Sun Shangchen , Zhang Yonghe , Zhao Wenqing , Wen Fei , Yang Guangrui
Published: January 2025

This study used experimental and computational approaches to investigate the adsorption behavior of seven heavy metal ions on Fh. The pH edge analysis revealed that the adsorption capacity followed the order: Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+ > Co2+ > Mn2+, with Pb2+ showed the highest adsorption.
Effect of pre-treatment conditions on the electrochemical performance of hard carbon derived from bio-waste
Authors: Mutiat Oniye Modupe , Alpysbayev Aibar , Abduakhitov Dilshat , Kudaibergenov Kenes , Bakenov Zhumabay , Myung Seung-Taek , Konarov Aishuak
Published: January 2025

This study examined the effect of the pretreatment on hard-carbon from coffee waste for sodium-ion batteries. Pre-oxidation at 150 °C showed 304 mA h g−¹ capacity and enhanced cycling stability.
Intramolecular noncovalent C-bonding driven conformational preference in spiroisatin-based N-acyl hydrazones
Authors: Ali Muhammad Imran , Hussain Javid , Anwar Muhammad Usman , Al-Harrasi Ahmed , Naseer Muhammad Moazzam
Published: January 2025

Intramolecular C-bond stabilizing the cis conformation of spiroisatin-based N-acyl hydrazones in solution highlights the role of weak intramolecular interactions in conformational preferences in supramolecular chemistry.
Ga-doping in Li0.33La0.56TiO3: a promising approach to boost ionic conductivity in solid electrolytes for high-performance all-solid-state lithium-ion batteries
Authors: Mahfuz Md. Nagib , Nura Appy Feroz , Islam Md Shafayatul , Saha Tomal , Chowdhury Koushik Roy , Hoque Sheikh Manjura , Gafur Md Abdul , Ahmed Aninda Nafis , Sharif Ahmed
Published: January 2025

Ga doping at the B-site of LLTO solid electrolytes significantly enhances ionic conductivity due to increased B–O bond length and larger grain size. This makes Ga-LLTO a promising candidate for high-performance all-solid-state lithium-ion batteries.
Layered perovskite-type Nd2Ti2O7 energy-storage ceramics with ultrahigh Eb (∼1.4 MV cm−1) and large Eg (∼3.76 eV)
Authors: Wang Tao , Feng Qin , Yuan Changlai , Qin Jiejie , Chen Xiyong , Jia Ronghao , Cen Zhenyong , You Hui , Hu Jianan , Luo Nengneng
Published: January 2025

Nd2Ti2O7 ceramics with simple compositions exhibit ultra-high breakdown electric fields and excellent energy storage performance. They also exhibit excellent frequency (0.1–200 Hz) and temperature (20–180 °C) stability.
Correction: Silver(i)–iodine cluster with efficient thermally activated delayed fluorescence and suppressed concentration quenching
Authors: Li Xiao , Wei Shan-Yue , Zhang Dong-Hai , Hu Jia-Xuan , Hou Chen-Lu , Lin Ting-Ting , Chen Xu-Lin , Lu Can-Zhong
Published: January 2025

Correction for ‘Silver(i)–iodine cluster with efficient thermally activated delayed fluorescence and suppressed concentration quenching’ by Xiao Li et al., Dalton Trans., 2025, https://doi.org/10.1039/d4dt02855d.
Venous Thromboembolism Occurrence and Association with Gastrointestinal Disorders in Children with Cystic Fibrosis: An Analysis from the TriNetX Research Network Global Multicenter Real-World Dataset
Authors: Trocchia Carolena , Ashour Dina , Mosha Maua , Hamner Bailey , Betensky Marisol , Goldenberg Neil , Khalaf Racha
Published: January 2025

The purpose of this study is to (1) estimate and compare the prevalence of venous thromboembolism (VTE) in children (age 0 to ≤21) with versus without cystic fibrosis (CF); (2) investigate putative associations between specific gastrointestinal (GI) manifestations and the development of VTE among children with CF. This was a multicenter case–control analysis among patients aged 0 to ≤ 21 years between 2010 and 2020, using the TriNetX Research Network. Data queries included ICD-9/10 (International Classification of Diseases-9th/10th Revision) diagnosis codes. Bivariate associations with VTE among CF patients were compared using Chi-square testing for categorical variables and Student's t-test for continuous variables. We used multivariable logistic regression to test for independent associations of GI manifestations with VTE among children with CF, with adjustment for other salient covariates. There was a total of 7,689 children with and 22,327,660 without CF. The frequency of occurrence of VTE was increased nearly 20-fold among those with, as compared with without CF (130 vs. 7 per 10,000 patients). Acute pancreatitis (adjusted odd ratio [aOR] = 3.80, [95% confidence interval, CI: 2.00–7.22]), biliary disease (aOR = 2.17 [95% CI: 1.17–4.03]), gastrostomy status (aOR = 2.01 [95% CI: 1.27–3.18]), and malabsorption/malnutrition (aOR = 2.41 [95% CI: 1.52–3.82]) were each associated with a higher likelihood of VTE among children with CF. In conclusion, we found a significantly increased frequency of VTE occurrence and association of specific GI diseases as independent risk factors for VTE among children with CF compared with those without.
Nonlinear acoustic emission in He II
Authors: Nemirovskii S. K.
Published: January 2025

The problem of generation and propagation of waves under mechanical or thermal perturbation of He II is solved by taking into account nonlinearity and thermal compressibility. It is shown that with both mechanisms of pumping there emerge two waves which transfer perturbations of all hydrodynamic quantities. The obtained quantitative relations make it possible to calculate the values of oscillating quantities.
Critical lines in anisotropic dielectric spin glasses
Authors: Efimova N. N. , Popkov Yu. A. , Tkachenko N. V.
Published: January 2025

Temperature-field dependences of the upper critical lines are investigated in Heisenberg spin glasses (SG) Li0.5Fe2.5−xGax O4 (GaxS), x = 1.50–1.6 and BaFe12−x GaxO19 (GaxM), x = 7.75−8.50, which differ considerably in the magnitude and mechanisms of anisotropy, but are similar in their exchange interaction. It is found that the critical behavior in both systems is determined by random anisotropy and is in perfect agreement with theoretical ideas: dependences of the type τ∝H2/3τ=1−Tf(H)/Tf(0) are observed in the weak-field limit, τ′∝H2τ′=1−Tf(H)/T˜f(0) in strong fields, and the intermediate field region corresponds to crossover. The line τ ∝ H2/3 in the weakly anisotropic system Gax S is determined by the critical dynamics and strong irreversibility of magnetic properties. The PM–SG phase transition along this line is described by the isotropic order parameter qEA. For a highly anisotropic GaxM system, the line τ ∝ H2/3 is determined only by the critical dynamics. In the crossover region and in the strong-field limit, the critical lines in both systems are determined by the critical dynamics and strong irreversibility.
Influence of high magnetic fields on the mechanical properties of metastable austenitic steels
Authors: Morris J. W. , Fultz B. , Chan J. W. , Mei Z.
Published: January 2025

This work was undertaken to explore the influence of high magnetic fields on the cryogenic mechanical properties of 304-type stainless steels, which are metastable austenitic steels that transform to martensite on plastic deformation at low temperature. The presence of a high magnetic field increases both the extent and the kinetics of the martensite transformation in 304-type stainless steels during plastic deformation at low temperature. The consequence is an earlier and more complete martensitic transformation in tensile specimens, and a more extensive transformation in the plastic field ahead of the crack tip in fracture toughness tests. For field strengths up to at least 18 T the magnetic field has a relatively small effect on the tensile behavior of 304-type stainless steels at 77 and 4 K. The mechanical effects that are observed primarily concern the work hardening rate which tends to be smaller at low strain and larger at moderate strain in the presence of the field. These effects are explainable in light of the increased rate of the martensite transformation. The measured fracture toughness of 304 stainless steel at 4 K increased significantly in the presence of an 8 T field. The direction of the change is consistent with existing theories of toughening by the martensitic transformation, since the extent of the transformation increases in the presence of the field. However, the magnitude of the increase is larger than these theories predict.
Observation of the kinetic diamagnetic effect in bismuth
Authors: Zhilyaev I. N.
Published: January 2025

A heat flux passing through a bismuth sample in a transverse magnetic field at helium temperatures gives rise to circulating currents whose magnetic field has a direction opposite to that of the applied field. This effect is explained by the presence of the Nernst–Ettingshausen emf gradient due to the temperature difference along the sample.
On the problem of the positive curvature of the temperature dependence of H
c2 in HTS
Authors: Lazarev B. G. , Lazareva L. S. , Chupikov A. A. , Tikhonovskii M. A. , Medoidze T. D.
Published: January 2025

The behavior of the R(T) curve in magnetic fields is studied comprehensively for some HTS samples. It is found that the positive curvature of the Hc2(T) curve is less pronounced for samples with a higher homogeneity (purity), i.e., is a property of a sample. The positive curvature for HTS samples, as well as for conventional metal superconductors (B.G. Lezarev and V.I. Khotkevich, Zh. Eksp. Teor. Fiz. 18, 807 (1948), and V. I. Khotkevich, D.Sc. Thesis, Kharkov (1952)), is due to impurities and inhomogeneities.
Effect of magnetic field on low-temperature heat capacity of CsDy(MoO4)2
Authors: Stefaniji P. , Orendaceva A. , Feger A. , Anders É. E. , Zvyagin A. I.
Published: January 2025

The heat capacity of CsDy(MoO4)2 is investigated in magnetic fields from 0 to 3 T with the field orientation along the principal crystallographic axes of the crystal in the temperature interval from 0.6 to 6 K. The behavior of heat capacity in weak fields indicates that spins are arranged along the c axis. A broad peak of Cp(T) is observed in two directions (H‖a and H‖c) in stronger fields, the orientations differing in the field dependence of the peak height. The model of perfect paramagnet with S = 1/2 has been used to determine the anisotropy of the effective g factor: gc = 12.8 ± 0.9 and ga = 8.9 ± 0.4.
Generating the true S-poly-Bargmann spaces by sliced creation operators and associated integral transforms
Authors: Bouali Lamya , Boudrai Sofia , Ghanmi Allal
Published: January 2025

We deal with an operational realization of the so-called n-th true S-poly-Bargmann space. We show that it can be realized as the range of the iterated sliced creation operator, and that it is close to the spectral analysis of a sliced magnetic Laplacian for which we provide a geometrical realization à la Hodge. Some integral representations of the considered spaces are also investigated.
Examining astrophysical gas cloud collapse using an optical depth-scaled, x-ray-irradiated, carbon-foam sphere
Authors: VanDervort R. W. , Klein Sallee , Trantham Matthew , Kozlowski Pawel M. , Keiter Paul A. , Drake R Paul , Kuranz Carolyn
Published: January 2025

When stellar radiation interacts with a molecular cloud, the cloud's fate depends on the strength of the incident radiation and the radiation's mean-free-path within the cloud [F. Bertoldi, Astrophys. J. 346, 735–755 (1989)]. Under the right conditions, the radiation compresses the cloud and a star formation may occur. Where and when the stellar formation occurs in the cloud's collapse are open questions. Direct observation of the complete star–cloud lifecycle is nearly impossible due to the immense timescales and distances over which the interaction occurs. Laboratory astrophysics offers a way to investigate such a system by scaling the important astrophysical parameters to the laboratory. This work describes laboratory experiments to study the radiation-driven implosion of clouds, using x rays from a laser-irradiated, thin, gold foil as a surrogate star and a carbon-foam sphere as a surrogate cloud. An optically thick system, theoretically corresponding to a star-forming regime, was selected by choice of the foam density. Gold foil and sphere motions were imaged by x-ray radiography. Radiographic images show the formation of an interface between rarefied gold and carbon plasmas, a shock moving into the sphere, and a blunting of the initial sphere's shape. Measurements show that the shock moved linearly around 64 μm/ns into the sphere, and the gold–carbon interface formed by 2 ns at the sphere edge remained stationary. The deformation of the sphere was driven by the incident radiation and not by mechanical pressures applied by gold plasma. The blunting of the sphere was likely due to the geometric reduction of flux near the sphere's poles. Higher x-ray flux near the sphere's equator caused high compression and a faster shock, which flattened the sphere. We will discuss the results and implications of our observations.
Optimal design of acoustic metamaterials for noise suppression by the frequency division in military equipment
Authors: Bi Shaohua , Yang Fei , Shen Xinmin , Peng Wenqiang , Yang Xiaocui , Yin Qin , Zhang Xiaonan , Zhang Heng , Wang Dong , Chen Jingguo , Li Zhiming
Published: January 2025

This paper presents a multi-Helmholtz unit series–parallel acoustic metamaterial with a segmented noise control effect designed by taking advantage of the adjustable frequency band of an acoustic metamaterial, aiming to change the main noise spectrum characteristics under different driving conditions of military equipment such as tanks. Based on the transfer matrix method, a theoretical model that can predict the acoustic characteristics of a hybrid structure with multiple Helmholtz resonator (HR) units is established, and its feasibility is verified through finite element simulations and experiments. By combining particle swarm optimization with finite element simulation, the suboptimal average sound absorption coefficient (αavg) of ten populations was 0.52, 0.54, 0.54, and 0.44, respectively, after iterating for 50 generations. The results demonstrate that the αavg of the four groups of HRs in series with three layers reaches 0.79, 0.62, and 0.66, respectively, at the frequency bands of 205–285, 540–720, and 940–1130 Hz, and the overall thickness of the longest part is 88 mm. Low-frequency noise at approximately λ/18 can be controlled. The HR obtained by means of the first series and then parallel can achieve accurate sound absorption for specific frequency bands and can reduce its volume by removing redundant absorption bands. The findings of this study provide an effective noise-control scheme for changing the noise environment in military equipment.
Hydrodynamic modes in nano-channels
Authors: Knudsen Solvej , Todd B. D. , Hansen J. S.
Published: January 2025

This paper investigates the local hydrodynamics of a dense fluid confined in nanoscale slit-pores with different heights. Using non-equilibrium molecular dynamics simulations of the fluid system, we induce a steady-state sinusoidal velocity profile across the channel having a characteristic wavelength, thus, probing the fluid response to a specific Fourier mode. As expected, for sufficiently large channel heights and wavelengths there is an excellent agreement between the hydrodynamic predictions and simulation data. As the wavelength decreases to around 5 molecular diameters, the classical hydrodynamics fails to predict the steady-state velocity profile; we attribute this to the non-local nature of the fluid response and the presence of density gradients in the wall–fluid interfacial region. Using generalized hydrodynamics and the Fourier spectrum of the density profile, we derive the strain rate amplitude and shear pressure corrections due to these two effects. The local relaxation from the steady-state to the zero flow situation is tracked for different channel heights and wavelengths. The relaxation is in general visco-elastic in the wall–fluid region, and we argue that this phenomenon is the mechanism behind the “enhanced viscosity” used in the literature. We also report a surprising dynamics for the fluid located between the wall–fluid region and bulk region, which cannot be explained by classical hydrodynamics; here, an initial exponential relaxation abruptly transitions into a linear relaxation. The work highlights the many different physical mechanisms present in nano-confined fluids, and that the fluid response is in general position and wavelength dependent.
A synaptic transistor with a stacked layer of SiNx and SiO2 deposited from hexamethyldisiloxane/O2
Authors: Peng Chong , Liu Yiming , Yu Cong , Zhao Yi
Published: January 2025

Herein, we employed inductively coupled plasma enhanced chemical vapor deposition using a hexamethyldisiloxane/O2 precursor to deposit SiO2 with electrical double layer capacitance on SiNx forming SiO2/SiNx stacked films as a dielectric layer, achieving high-performance synaptic transistors. The effect of O2 concentration during SiO2 deposition on the transistor performance was investigated. The results of Fourier transform infrared spectroscopy and x-ray photoemission spectroscopy confirm that increasing O2 concentration during deposition boosts the amounts of protons moving between the bridging oxygen in the Si–O–Si network, improving the electrical double layer capacitance of SiO2. Furthermore, SiNx in the stacked structure exhibits a higher relative permittivity than SiO2, resulting in a more concentrated electric field within the SiO2 layer, facilitating proton ionization. SiO2/SiNx stacked film with SiO2 deposited at the oxygen flow rate of 150  sccm exhibited the maximum capacitance of 2.87 μF/cm2 at 4 Hz. The transistor with SiO2 deposited at the oxygen flow rate of 150  sccm achieved the maximum paired pulse facilitation index of 132.9% and the maximum A50/A1 index of 155.4%. This work demonstrates that SiO2 deposited via inductively coupled plasma enhanced chemical vapor deposition using a hexamethyldisiloxane/O2 precursor for application potential in artificial neuromorphic computing.
Design of an adjustable low-temperature linear microwave plasma source for atmospheric pressure applications
Authors: Qu Ao , Chen Yan , Zhang Nian , Wu Li
Published: January 2025

Linear plasmas, compared to small-area low-temperature plasma jets, offer a larger single-treatment area with a brush-like pattern, making them highly promising for various applications. This paper introduces the design of an adjustable low-temperature linear plasma source that operates under atmospheric pressure at 2.45 GHz. The design integrated microwave theory with dielectric barrier discharge principles, utilizing a resonant structure based on a microstrip power divider with one end open and the other shorted. The ground plane of the microstrip structure was replaced by a metal plate featuring a large groove. Argon gas was introduced from the short-circuited end and exited through the groove at the open end, where plasma excitation occurred. Experimental results demonstrated that the device, operating at atmospheric pressure, can achieve adjustable linear plasma widths ranging from 10 mm to 50 mm by varying the incident power between 30 and 100 W. Optical emission measurements confirmed the uniformity of the linear plasma, and the gas temperature 5 mm away from the discharge area remained at only 65 °C, even with a microwave incident power of 100 W. This study offers a novel approach to designing linear atmospheric pressure microwave plasma sources, with significant potential for diverse material treatment applications.
Highly sensitive and efficient 1550 nm photodetector for room temperature operation
Authors: Rituraj  , Yu Zhi Gang , Kandegedara R. M. E. B. , Fan Shanhui , Krishnamurthy Srini
Published: January 2025

Photonic quantum technologies such as effective quantum communication require room temperature (RT) operating single- or few-photon sensors with high external quantum efficiency (EQE) at 1550 nm wavelength. The leading class of devices in this segment is avalanche photodetectors operating particularly in the Geiger mode. However, for superior performance, a trade-off has to be made between temperature of operation, device thickness, and EQE. Two-dimensional (2D) materials can be used to reduce the absorber thickness and thus dark current, leading to an increase in the operating temperature, but they suffer from low EQE. We use specifically stacked bilayer hexagonal BAs, with material properties calculated from first principles, on a co-optimized dielectric photonic crystal substrate to simultaneously decrease the dark current by three orders of magnitude at RT and maintain an EQE of >99%. The device can potentially be used in avalanche mode and hence can form a basis for single photon detection.
Denoising of ceramic detection signals based on the combination of variational modal decomposition optimized by improved secretary bird optimization algorithm and wavelet thresholding
Authors: Luan Jianping , Liu Liping , Cui Bo
Published: January 2025

In response to the problem of noise interference in the knock detection signal received by the pickup in the ceramic sheet knock non-destructive testing, a noise removal method is proposed based on the improved secretary bird optimization algorithm (ISBOA) optimized variational mode decomposition (VMD) combined with wavelet thresholding. First, the secretary bird optimization algorithm is improved by using the Newton–Raphson search rule and smooth exploitation variation strategy. Second, the ISBOA is used to select the key parameters in the VMD. Third, the signal is subjected to the VMD decomposition to obtain the intrinsic mode functions (IMFs), and permutation entropy of each IMF component is calculated to divide it into effective signal component or noise component. Finally, the effective signal component is denoised by using improved wavelet thresholding, and the processed IMFs components are reconstructed to obtain the denoised signal. The denoising of simulated signal with 5 dB signal-to-noise ratio shows that the signal-to-noise ratio of the signal is improved by 11.59 dB and the root mean square error is reduced by 73.6%, which is the most significant denoising effect of the method compared to other similar algorithms. In addition, tests on the knock detection signals of ceramic pieces with different types of defects also show that the method has wide applicability and an excellent denoising effect.
The influence of parameters on the hydrodynamic characteristics of oscillating water column devices: A numerical study
Authors: Qu Ming , Bao Xingxian , Bao Jian , Wang Maojie
Published: January 2025

The influence of parameters on the hydrodynamic characteristics of OWC (oscillating water column) devices exhibits a coupling phenomenon, which is frequently neglected. To elucidate the comprehensive influence and its mechanism of structure parameters on the hydrodynamic characteristics of offshore OWC devices, a structure with a bottom plate was selected in this study. Through numerical simulation, the hydrodynamic characteristics of the chamber with variations in PTO (power take off) coefficient α, chamber length Bs, internal depth Jn, and under water length of front wall Je with different wave conditions are investigated. The following conclusions are primarily drawn: The research method of using the relative wavelength L/Bs as a non-dimensional parameter and solely varying the wavelength L has its drawbacks. In cases that L/Bs is held constant, the efficiency of chambers differing only in Bs can vary by more than 70%. The influence of each parameter on the effectiveness is interrelated. Chambers with a lower α exhibit a more pronounced impact of Bs. The efficiency of device with a smaller relative wavelength L/Bs is more significantly affected by the Jn. The mechanism by which the parameters affect efficiency is primarily since chambers with shorter Bs or greater Jn exhibit smaller deformations during internal liquid surface oscillation, resembling a more uniform oscillating water column. This allows more energy to be utilized for pushing air in and out of the chamber above, thereby enhancing the energy conversion capability. The results of this research can provide valuable insights for the design of OWC devices.
Spintronic effects and devices in nonlinear optics
Authors: Bashan Gil , Izhak Shani , Yesharim Ofir , Arie Ady
Published: January 2025

In this perspective article, we discuss the analogy between spin transport in magnetization texture and the nonlinear process of sum frequency generation, where the signal and idler complex amplitudes represent the two-dimensional spinor, while the nonlinear coupling represents the material magnetization. This analogy unveils new nonlinear optical effects in both spatial and temporal domains, including the analog of the famous Stern–Gerlach effect, the topological Hall effect in magnetic skyrmion structures, and the transverse localization of spin currents in a disordered magnetic spin-glass phase. Moreover, it enables us to realize new all-optical devices that manipulate superposition states of the signal and idler. Examples include a pump-controlled spin valve, which can either reflect or transmit the signal-idler waves when they are in-phase, and a spin waveguide that guides only in-phase signal-idler waves.
Write error reduction in magnetic tunnel junctions for voltage-controlled magnetoresistive random access memory by using exchange coupled free layer
Authors: Sakai Lui , Higo Yutaka , Hosomi Masanori , Matsumoto Rie , Nozaki Takayuki , Yuasa Shinji , Imamura Hiroshi
Published: January 2025

Voltage-controlled magnetoresistive random access memory (VC-MRAM) is an emerging nonvolatile memory based on the voltage-controlled magnetic anisotropy (VCMA) effect. It has been garnering considerable attention because of its fast and low-power operation. However, two major issues must be addressed for practical applications. First, the voltage-induced switching of the free layer magnetization is sensitive to ultrashort voltage pulse duration. Second, the write error rate (WER) of the voltage-induced switching is high. To address these issues, a magnetic tunnel junction (MTJ) structure with an exchange coupled free layer, consisting of a precession layer with the VCMA effect and an anchor layer without the VCMA effect, is proposed. The anchor layer prevents the precession layer from returning to its initial direction, thereby reducing the WER without requiring the voltage pulse duration to be precisely controlled. The write operation of the proposed MTJ with an exchange coupled free layer was analyzed using the macrospin model. Using optimized MTJ parameters, a low WER of approximately 10−6 was obtained for an 80 nm MTJ without requiring the pulse duration to be precisely controlled. These results facilitate the reduction of the WER for VC-MRAM and improve its usability, thereby expanding its range of applications.
Numerical investigation of the influence of pulse frequency on the weld pool size in pulsed current TIG welding
Authors: Parvez Shahid , El Rayes Magdy , Al-Bahkali Essam , Alqosaibi Khalid
Published: January 2025

This study simulates the pulsed current tungsten inert gas (TIG) welding process to investigate the transient development of the weld pool in a 4 mm thick aluminum sheet, focusing on the effects of pulse frequency on the weld pool size. Two pulsed currents, 230 and 180 A, with a 30% background current, were examined. The 230 A current achieved full, while the 180 A resulted in partial penetration. Five pulse frequencies (1, 4, 10, 20, and 50 Hz) were analyzed. A numerical model was developed to compute heat and current fluxes on the workpiece surface. The arc profile shifted from a bell shape in high-frequency cycles to a conical shape in low-frequency cycles. The heat and current fluxes served as inputs to another model that simulated weld pool behavior for both direct and pulsed current TIG welding. The results showed that weld pool size decreased in pulsed current TIG welding. At 230 A, full penetration changed to partial penetration under pulsed current. At 1 Hz, sufficient time was available for solidification during the low-cycle period, but at 50 Hz, the weld pool remained liquid. As pulse frequency increased from 1 to 50 Hz, the weld pool depth decreased significantly, with a reduction from 2.4 to 0.9 mm at 230 A and from 1.1 to 0.34 mm at 180 A. Convection in the weld pool was influenced by temperature and was strongest at higher temperatures. The decrease in weld pool size was most pronounced between 1 and 10 Hz, stabilizing between 20 and 50 Hz. Validation against experimental macrographs demonstrated good agreement with the simulations.