bluuebunny/crossref_metadata_2025 huggingface dataset:
Matrix Biology: Structure and Assembly of Laminin-Rich Matrices
Authors: Hamill Kevin J. , Hopkinson Susan B. , Hill Natalie M. E. , Jones Jonathan C. R.
Published: October 2024

In this review we focus on one of the most diverse families of matrix molecules, namely the laminins. Their diversity and the fact that their expression is tightly regulated during development and tissue remodeling would indicate that they are central to tissue organization. We will detail laminin structure, expression profiles, and outline the diseases which are a result of their aberrant expression and/or function. We will also describe laminin network formation, signaling regulated by laminin–cell-surface receptor interactions, and modification of laminin functionality through laminin-binding proteins. Understanding the biology of the laminins, how they assemble, and the nature of their binding partners is crucial, since laminins are widely used as substrates for the culture of cells in vitro and are being developed for use in bioengineering and clinical applications in vivo. Hence, we will provide information on the types, functions and interactions of laminins currently available from commercial and academic sources or whose recombinant production has been described. Finally, we will discuss the potential use of laminins in tissue engineering, focusing on their utility to enhance material cellularization.
Metalloporphyrinic metal–organic frameworks for enhanced photocatalytic degradation of a mustard gas simulant
Authors: Quon Alisa S. , Manriquez Doroteo , Nguyen Anna , Papazyan Edgar K. , Wijeratne Pavithra , An Lun , Qi Long , Tang Matthew J. , Ready Austin D. , Farha Omar K. , Liu Yangyang
Published: October 2024

A tin-porphyrin functionalized 2D metal–organic framework has been developed and exhibits one of the fastest rates for the photooxidative degradation of a mustard gas simulant.
Atomistic insight into the promising thermoelectric performance of the copper-based ternary phosphide CaCuP
Authors: Jong Un-Gi , Ryu Chol , Hwang Ji-Min , Kim Su-Hyang , Ju Il-Gwang , Yu Chol-Jun
Published: October 2024

We provide a valuable atomistic insight into the thermoelectric properties of hexagonal CaCuP, revealing that nano-structuring can double the thermoelectric figure of merit by further reducing lattice thermal conductivity.
Flow-gel approach enables rapid extraction of pure magnesium phase from seawater
Authors: Butreddy Pravalika , Ritchhart Andrew , Wang Qingpu , Job Heather , Sushko Maria L. , Chun Jaehun , Nakouzi Elias
Published: October 2024

Chemical separations are achieved by flowing a feedstock solution on top of a gel loaded with a precipitating agent.
First-principles study on the lithiation process of amorphous SiO anode for Li-ion batteries with Bayesian optimization
Authors: Shintaku Ryoya , Tamura Tomoyuki , Nogami Shogo , Karasuyama Masayuki , Hirose Takakazu
Published: October 2024

Bayesian optimization allows theoretical investigation of the lithiation process of amorphous SiO anode materials for lithium (Li) ion batteries (LIBs).
Computational insight into the peptide-based inhibition of α-cobratoxin
Authors: Mitra Aritra , Pandijothi Viswas , Paul Sandip
Published: October 2024

An 8-mer peptide (YMWDGWYM) binds to two units of α-cobratoxin in a sequential manner, with the N-terminal YM binding first followed by the C-terminal YM, masking residues of the toxin responsible for binding to the nicotinic acetylcholine receptor.
Insights into the chirality-dependent recognition of Danshensu Bingpian Zhi stereoisomers with PPARγ
Authors: Zhao Jiasheng , Zhao Yizhen , Zhang Shengli , Zhang Lei , Yang Zhiwei
Published: October 2024

Danshensu Bingpian Zhi (DBZ) stereoisomers show distinct binding modes and efficacies, impacting the conformational changes of PPARγ, emphasizing the role of chiral recognition in the protein–ligand interactions.
Retraction: Unprecedented O:⇔:O compression and H↔H fragilization in Lewis solutions
Authors: Sun Chang Q.
Published: October 2024

Retraction of ‘Unprecedented O:⇔:O compression and H↔H fragilization in Lewis solutions’ by Chang Q. Sun, Phys. Chem. Chem. Phys., 2019, 21, 2234–2250, https://doi.org/10.1039/C8CP06910G.
Electroanalytical characterization of Np(vi)/Np(v) redox in a pentadentate ligand environment and stabilization of [NpVO2]+ by hydrogen bonding
Authors: Mikeska Emily R. , Curry T. Davis , Wilson Richard E. , Blakemore James D.
Published: October 2024

Np(vi/v) redox in a molecular complex was probed in protic and aprotic organic media with electroanalytical, spectroscopic, and structural work. Insights into the reversible electron transfer to interconvert Np(vi) and Np(v) have been obtained.
Recent advances in the electrochemical functionalization of N-heterocycles
Authors: Yadav Manoj Kumar , Chowdhury Sushobhan
Published: October 2024

The review aims to provide a clear picture of the possible electron transfer pathways, electrochemical behavior of different N-heterocycles, and functionalization reagents to achieve the desired functionalization/modification of N-heterocycles.
Enhanced mechanical strength of polypropylene bionanocomposites through spray-dried nanocrystalline cellulose reinforcement
Authors: Sabaruddin Fatimah Athiyah , Ariffin Hidayah , Shazleen Siti Shazra , Ng Yee Foong Lawrence , Rujitanaroj Pim-on , Thitiwutthisakul Kasinee , Permpaisarnsakul Patcharin , Tinnasulanon Phungjai
Published: October 2024

The production of PP/SD-NCC bionanocomposites through one- and two-step compounding processes and their corresponding analytical finding.
Correction: Charge transfer properties of novel linear carbon chain-based dyes
Authors: Consiglio Giuseppe , Gorczyński Adam , Petralia Salvatore , Forte Giuseppe
Published: October 2024

Correction for ‘Charge transfer properties of novel linear carbon chain-based dyes’ by Giuseppe Consiglio et al., J. Mater. Chem. C, 2024, 12, 903–912, https://doi.org/10.1039/D3TC03740A.
Understanding metabolic plasticity at single cell resolution
Authors: Abbate Christina C. , Hu Jason , Albeck John G.
Published: October 2024

It is increasingly clear that cellular metabolic function varies not just between cells of different tissues, but also within tissues and cell types. In this essay, we envision how differences in central carbon metabolism arise from multiple sources, including the cell cycle, circadian rhythms, intrinsic metabolic cycles, and others. We also discuss and compare methods that enable such variation to be detected, including single-cell metabolomics and RNA-sequencing. We pay particular attention to biosensors for AMPK and central carbon metabolites, which when used in combination with metabolic perturbations, provide clear evidence of cellular variance in metabolic function.
Symbol detection aided channel prediction in fast‐varying massive MIMO systems: Framework and performance analysis
Authors: Gao Wei , Xiao Junqiang , Liu Chuan , Peng Wei
Published: October 2024

The channel in massive multiple‐input multiple‐output systems is fast‐varying that the pilot signal needs to be sent frequently. To obtain timely channel state information with less pilot overheads, a symbol detection aided channel prediction scheme is proposed in this paper. Then, the prediction error lower bound of the proposed scheme within one interval of effective prediction is analysed. Besides, the approximate close‐form post‐processing signal to noise ratio is derived for zero‐forcing detector with imperfect channel predictions. Numerical simulations are implemented to verify the validity of theoretical analysis. The results show that the theoretical expressions have a close match with the real simulated performance under various simulation parameter settings. In addition, the frequency of transmitting the pilot signals can be significantly reduced when adopting this proposed method. Moreover, the application of the proposed scheme can be further expanded when combining it with channel coding, thereby greatly improving the spectrum efficiency of the system.
A hybrid variational level set model based on double Gaussian distribution fitting energy for image segmentation and bias correction
Authors: Tang Liming , Zhang Honglu , Xu Yaya , Ren Yanjun , Li Chunyan
Published: October 2024

The variational level set model has been widely used in image segmentation. However, its performance is significantly hindered by bias fields and noise within the images. To address these limitations, we introduce a novel hybrid variational level set model based on dual Gaussian distribution fitting (DGDF) energy in this paper. The DGDF energy integrates both local and global Gaussian distributions. The local energy is derived from the original image, while the global energy employs the corrected image, enabling effective segmentation of images with intensity inhomogeneity. Furthermore, the model demonstrates low sensitivity to weighting parameters and robust performance for noisy images. We develop an alternating iteration algorithm that combines variational methods with gradient descent to efficiently solve the proposed model. Experimental results validate the effectiveness of the model and the algorithm. In addition, the proposed model shows competitiveness on test images and three datasets compared to several state‐of‐the‐art models, including other variational level set models and deep learning‐based techniques.
DMA‐Net: A dual branch encoder and multi‐scale cross attention fusion network for skin lesion segmentation
Authors: Zhai Guangyao , Wang Guanglei , Shang Qinghua , Li Yan , Wang Hongrui
Published: October 2024

Automatic segmentation of skin lesion is an important step in computer‐aided diagnosis. However, due to the significant variations in the size and shape of the lesion areas, as well as the low contrast with normal skin tissue, the boundaries are not clearly distinguishable, leading to a high possibility of incorrect segmentation. Therefore, this task is highly challenging. To overcome these difficulties, this paper proposes a medical image segmentation architecture named dual branch encoder and multi‐scale cross attention fusion network, which includes a dual‐branch encoder based on convolutional neural network and an improved channel‐enhanced Mamba to comprehensively extract local and global information from dermoscopy images. Additionally, to enhance the feature interaction and fusion of local and global information, a multi‐scale cross attention fusion module is adopted to cross‐merge features in different directions and at different scales, maximizing the advantages of the dual‐branch encoder and achieving precise segmentation of skin lesions. Extensive experiments are conducted on three public skin lesion datasets: ISIC‐2018, ISIC‐2017, and ISIC‐2016, to verify the effectiveness and superiority of the proposed method. The dice similarity coefficient scores on the three datasets reached 81.77%, 81.68% and 85.60%, respectively, surpassing most state‐of‐the‐art methods.
Identification of transmission line voltage sag sources based on multi‐location information convolutional transformer
Authors: Li Qionglin , Zheng Chen , Liu Shuming , Dai Shuangyin , Zhang Bo , Tang Yuzheng , Wang Yi
Published: October 2024

Conventional methods for identifying voltage sag sources are difficult to categorize accurately due to the complexity of transmission lines and the influence of noise. In order to solve the problem of difficulty in recognizing voltage sag sources of transmission lines under different locations, this paper proposes a new method for transmission line fault diagnosis based on modified wavelet denoising and multi‐location information convolution transformer. The improved wavelet denoising method proposed in this paper solves the problems of discontinuity and bias of the traditional wavelet denoising method, and is able to better reconstruct the original voltage signal in a strong noise environment. In addition, multi‐location information convolution transformer adopts a new model combining multi‐location information convolution and multi‐scale convolution transformer, which realizes the combination of global information and local context information capturing ability under multi‐location faults. This paper validates the method through simulation experiments and practical situations, and the results show that the method can well classify and identify the type and location of voltage sag sources in transmission lines.
Origin of the spectral features observed in the cosmic-ray spectrum
Authors: Recchia S. , Gabici S.
Published: October 2024

Context. Recent measurements reveal the presence of several features in the cosmic-ray (CR) spectrum. In particular, the proton and helium spectra exhibit a spectral hardening at ≈300 GV and a spectral steepening at ≈15 TV, followed by the well-known knee-like feature at ≈3 PV. The spectra of heavier nuclei also harden at ≈300 GV, while no claim can be currently made about the presence of the ≈15 TV softening, due to low statistics. In addition, the B/C ratio also exhibits a hardening at ≈100 GeV/n and seems to be rather shallow at ≈1 TeV/n

Aims. We propose a possible explanation of the observed spectral features in the framework of a composite diffusion scenario and considering different classes of sources.

Methods. The proposed scenario is based on two assumptions. First, in the Galactic disk, where magnetic field lines are mainly oriented along the Galactic plane, particle scattering is assumed to be very inefficient. Therefore, the transport of CRs from the disk to the halo is set by the magnetic field line random walk induced by large-scale turbulence. Second, we propose that the spectral steepening at ≈15 TV is related to the typical maximum rigidity reached in the acceleration of CRs by the majority of supernova remnants, while we assume that only a fraction of sources, contributing to ≈10 − 20% of the CR population, can accelerate particles up to ∼PV rigidities.

Results. Within this framework we show that it is possible to reproduce the proton and helium spectra from GV to multi-PV; the p/He ratio; the spectra of CRs from lithium to iron; the p̄ flux and the p̄/p ratio; and the abundance ratios B/C, B/O, C/O, Be/C, Be/O, and Be/B. We also discuss the 10Be/9Be ratio in view of the recent AMS02 preliminary measurements.
Observational studies of S-bearing molecules in massive star-forming regions
Authors: Luo R. , Wang J. Z. , Zhang X. , Quan D. H. , Jiang X. J. , Li J. , Gou Q. , Li Y. Q. , Xu Y. N. , Zheng S. Q. , Ou C. , Liu Y. J.
Published: October 2024

Context. S-bearing molecules are powerful tools for determining the physical conditions inside a massive star-forming region. The abundances of S-bearing molecules, including H2S, H2CS, and HCS+, are highly dependent on physical and chemical changes, which means that they are good tracers of the evolutionary stage of massive star formation.

Aims. We present observational results of H2S 110-101, H234S 110-101, H2CS 514-414, HCS+ 4-3, SiO 4-3, HC3N 19-18, and C18O 1-0 toward a sample of 51 late-stage massive star-forming regions, and study the relationships between H2S, H2 CS, HCS+, and SiO in hot cores. We discuss the chemical connections of these S-bearing molecules based on the relations between the relative abundances in our sources.

Methods. H234S 110-101, as the isotopic line of H2S 110-101, was used to correct the optical depths ofH2S 110-101. Beam-averaged column densities of all molecules were calculated, as were the abundances of H2S, H2CS, and HCS+ relative to H2, which were derived from C18 O. Results from a chemical model that included gas, dust grain surface, and icy mantle phases, were compared with the observed abundances of H2S, H2CS, and HCS+ molecules.

Results. H2S 110-101, H234S 110-101, H2CS 514-414, HCS+ 4-3, andHC3N 19-18 were detected in 50 of the 51 sources, SiO 4-3 was detected in 46 sources, and C18O 1-0 was detected in all sources. The Pearson correlation coefficients between H2CS and HCS+ normalized by H2 and H2S are 0.94 and 0.87, respectively, and a tight linear relationship with a slope of 1.00 and 1.09 is found; this relationship is 0.77 and 0.98 between H2S and H2CS and 0.76 and 0.97 between H2S and HCS+. The full widths at half maxima of H234S 110-101, H2CS 514-414, HCS+ 4-3, and HC3N 19-18 in each source are similar to each other, which indicates that they may trace similar regions. By comparing the observed abundance with model results, we see that there is one possible time (2−3 × 105 yr) a which each source in the model matches the measured abundances of H2S, H2CS, and HCS+. The abundances of HCS+, H2CS, and H2S increase with the SiO abundance in these sources, which implies that shock chemistry may be playing a large role.

Conclusions. The close abundance relation of H2S, H2CS, and HCS+ and the similar line widths in observational results indicate that these three molecules could be chemically linked, with HCS+ and H2CS the most correlated. The comparison of the observational results with chemical models shows that the abundances can be reproduced for almost all the sources at a specific time. The observational results, including the abundances in these sources need to be considered in further modeling of H2S, H2CS, and HCS+ in hot cores with shock chemistry.
Assessing methods for telluric removal on atmospheric retrievals of high-resolution optical exoplanetary transmission spectra
Authors: Maguire Cathal , Sedaghati Elyar , Gibson Neale P. , Smette Alain , Pino Lorenzo
Published: October 2024

Context. Recent advancements in ultra-stable ground-based high-resolution spectrographs have propelled ground-based astronomy to the forefront of exoplanet detection and characterisation. However, the resultant transmission and emission spectra of exoplanetary atmospheres are inevitably contaminated by telluric absorption and emission lines due to the light’s transmission through the Earth’s atmosphere above the observatory. Retrieving accurate atmospheric parameters depends on accurate modelling and removal of this telluric contamination while preserving the faint underlying exoplanet signal.

Aims. There exist many methods to model telluric contamination, whether directly modelling the Earth’s transmission spectrum via radiative transfer modelling, or using a principal component analysis (PCA)-like reconstruction to fit the time-invariant features of a spectrum, and removing these models from the observations. We aimed to assess the efficacy of these various telluric removal methods in preserving the underlying exoplanetary spectra.

Methods. We compared two of the most common telluric modelling and removal methods, MOLECFIT and the PCA-like algorithm SYSREM, using planetary transmission spectra injected into three high-resolution optical observations taken with ESPRESSO. These planetary signals were injected at orbital periods of P =2 days and P = 12 days, resulting in differing changes in radial velocity during transit. We then retrieved various injected atmospheric model parameters in order to determine the efficacy of the telluric removal methods, as well as their effect on the transmission spectra of exoplanets with varying orbital architectures.

Results. For the close-in, high velocity injected signal, we found that SYSREM performed better for species that are also present in the Earth’s atmosphere-with accurate and precise retrieval of atmospheric abundances and T-P profiles, across each of the datasets. As we moved to slower moving signals at larger orbital separations, for one of the three datasets, SYSREM dampened the planetary H2O signal, leaving the retrieved abundance value unconstrained. In contrast, the H2O signal was preserved for the telluric modelling method, MOLECFIT. However, this behaviour was not ubiquitous across all three of the injected datasets, with another dataset showing a more precise H2O/Fe ratio when preprocessed with SYSREM. These conflicts highlight the importance of testing individual high-resolution dataset reduction routines independently to ensure real exoplanetary signals are preserved.
Fast magnetohydrodynamic oscillations of a coronal loop embedded in a potential coronal arcade
Authors: Lopin I. P.
Published: October 2024

Context. Observations indicate variable widths exhibited by fan coronal loops and flare loops that tend to widen towards the apex. Short-period, quasi-periodic pulsations in solar flares are often interpreted in terms of the fast-sausage oscillations of flare loops and the collective vertical vibrations of arcade loops are attributed with the vertical kink mode. Both phenomena are used as a seismological tool to estimate the physical parameters in the corona.

Aims. We performed an analytical study of fast sausage and kink oscillations in coronal loops, given the effects of loop curvature, expansion, and Alfvén speed variation.

Methods. We modelled a coronal loop as a dense expanding curved magnetic slab embedded within a potential coronal arcade, using a zero-β plasma limit. We obtained the dispersion relation that governs fast waves in the model and studied it both numerically and analytically.

Results. The effects of loop expansion and variable Alfvén speed reduce the cut-off frequency and increase the cut-off wavenumbers for fast sausage and kink waves. Moreover, the principal vertical kink mode has a cut-off and strongly attenuates in the leaky regime. The frequency increase is found to be minor for the global sausage mode both in the trapped and leaky regimes, with a frequency shift within a few percent. We found that in our model, where the Alfvén speed increases from the footpoints to the loop top, the spatial profile of the longitudinal fundamental is broadened and the antinodes of the first overtone are shifted towards the footpoints.

Conclusions. Using the classical expression for the cut-off wavenumber of the global sausage mode in a straight waveguide results in an underestimation of the density contrast constraint in flare loops. Instead, the suggested formula accounting for variations in loop widths provides more accurate results. The frequency of the global sausage mode can be correctly determined with the straight slab model.
Pitfalls in the assessment of higher education learning gains in Brazil through multilevel regression: handling the ceiling effect
Authors: Lins Marcos Estellita , Camara Musbah Koleilat , de Souza Ana Luiza Lima
Published: October 2024

This work assesses the validity of the Brazilian Indicator of the Difference between Observed and Expected Performances (IDD), which applies a multilevel regression model to rank university courses. It proposes a methodology to test for inconsistencies and research for the causes. With this objective, we develop an experimental methodology, applied to a database with 4432 production engineering students distributed over 329 undergraduate courses, from the government’s National Institute for Educational Studies and Research. We display a graphical analysis of the expected and achieved grades in final graduation exams, the gap in which determines the learning gains for every course. Then we apply the multilevel linear regression model of the IDD in a particular scenario, to test for consistency in value-added learning measurements using the technique reductio ad absurdum. The result reveals that the present methodology for the calculation of the IDD is inadequate and inconsistent, and that this can be explained by the ceiling effect. It needs to be radically revised to prevent unfair judgements. Finally, we propose and implement a production frontier technique to correct for the ensuing ceiling effect, namely a variable returns to scale data envelopment analysis model for adjusting the measurements using evidence based benchmarks.
Experimental narratives: A comparison of human crowdsourced storytelling and AI storytelling
Authors: Beguš Nina
Published: October 2024

The paper proposes a framework that combines behavioral and computational experiments employing fictional prompts as a novel tool for investigating cultural artifacts and social biases in storytelling both by humans and generative AI. The study analyzes 250 stories authored by crowdworkers in June 2019 and 80 stories generated by GPT-3.5 and GPT-4 in March 2023 by merging methods from narratology and inferential statistics. Both crowdworkers and large language models responded to identical prompts about creating and falling in love with an artificial human. The proposed experimental paradigm allows a direct and controlled comparison between human and LLM-generated storytelling. Responses to the Pygmalionesque prompts confirm the pervasive presence of the Pygmalion myth in the collective imaginary of both humans and large language models. All solicited narratives present a scientific or technological pursuit. The analysis reveals that narratives from GPT-3.5 and particularly GPT-4 are more progressive in terms of gender roles and sexuality than those written by humans. While AI narratives with default settings and no additional prompting can occasionally provide innovative plot twists, they offer less imaginative scenarios and rhetoric than human-authored texts. The proposed framework argues that fiction can be used as a window into human and AI-based collective imaginary and social dimensions.
Microscale chemiresistive hydrogen sensors: Current status and recent developments
Authors: Li Lu , Wang Zilun , Chang Ye
Published: October 2024

Hydrogen is known for its efficient combustion, abundant natural availability, and environmentally friendly characteristics. It is recognized as a promising energy source for the future and is already utilized in various industries, including petrochemicals, electronics, food processing, aerospace, and new energy vehicles. However, challenges arise in the storage and use of hydrogen owing to its tendency to leak, its potential for explosion within a specific concentration range of 4%–75%, and itslow ignition energy requirements. Consequently, there is a demand for hydrogen sensors capable of quickly and accurately detecting low levels of hydrogen leaks. Microelectromechanical systems-based chemiresistive hydrogen sensors offer advantages such as low cost, compact size, low energy consumption, and superior sensing performance, making them a major focus of recent research. This article provides a comprehensive overview and comparison of the sensing principles of various hydrogen sensors, including chemiresistive sensors, electrochemical sensors, thermocatalytic sensors, acoustic sensors, and mechanical sensors. Micro-chemiresistive hydrogen sensors exhibit high sensitivity, low cost, and ease of integration, making them highly promising for practical applications. In response to the challenges encountered in practical applications of chemiresistive hydrogen sensors, such as high operating temperatures and high power consumption, this review explores emerging trends in chemiresistive hydrogen sensor technology from the perspectives of novel materials and activation methods. Finally, it discusses the applications and potential further developments of chemiresistive hydrogen sensors.
Dynamic modeling and failure mechanism study of herringbone gear planetary transmission system for wind turbine under gear cracks
Authors: Bi Yue , Dong Hao , Liu Sheng-Sheng , Zhao Dai-Ning , Han Hao , Zhang Dong-Bo , Hou Xiang-Ying , Jin Guang-Hu
Published: October 2024

The herringbone gear planetary transmission system (HGPTS) is a common component in the gearbox of wind turbines. Studying the dynamic performance of gear systems is the key to improving their stability. To reveal the influence of cracks on the dynamic characteristics of the HGPTS, using slicing method, we explore the influence of different crack factors on the time-varying meshing stiffness (TVMS) of the system. A 55-degrees of freedom bending torsion axis pendulum dynamic model was constructed using the centralized mass parameter method; in the model, factors such as TVMS of cracks as well as receding groove and errors are considered. The Runge–Kutta method was used to solve the dynamics, and the evolution diagram of the vibration and load distribution characteristics of the system under crack changes was obtained. Vibration tests were conducted on the system studied in this work. The results show that under the influence of cracks, the TVMS of the external and internal meshing pairs of the system will decrease, and as the cracks intensify, the fluctuation of the TVMS will decrease. Cracks can lead to regular impact behavior in the system. A modulation sideband centered on the meshing frequency appears in the vibration response, and the vibration trajectory of the gears will also become disordered, at the same time, under the influence of cracks, there are significant excitation factors in the load-sharing characteristics of the system. As the cracks continue to intensify, the vibration of the system becomes increasingly evident, and the load-sharing characteristics show a trend of first decreasing and then increasing. The vibration test results are in good agreement with the theoretical predictions. The correctness of the established model is verified. The research results can provide reference for the reliability research of wind turbine HGPTS.
One-dimensional model for vertical hydraulic transport of high-concentration mineral particles
Authors: Zhang Ri , Wang Yumiao , Liu Lei , Guo Xiaoqi , Liu Yong , Liu Haixiao
Published: October 2024

A novel model is proposed for analyzing high-concentration granular flow systems comprising equally sized spherical particles within vertical, long straight pipelines. This model is specifically tailored for simulating the vertical hydraulic transport of ore particles in marine mining projects. The proposed model treats the granular system akin to a pseudo-fluid and operates through three mechanisms. First, fluid characteristics of the granular system are derived from particle–particle collisions. Second, the resistance exerted by the pipe wall on the granular system is calculated based on the momentum loss of particles during particle–wall collisions. Third, the interaction between individual particles and the surrounding fluid is transformed into an interaction between the carrier fluid and the pseudo-fluid. Additionally, the present work develops a dedicated numerical format and iterative method for solving the one-dimensional two-fluid governing equations. The one-dimensional (1D) model notably enhances computational efficiency and facilitates accurate tracking of high-concentration particles over extended distances within straight pipelines. Notably, the proposed 1D model demonstrates a high degree of predictive accuracy when compared against experimental data as well as results from computational fluid dynamics and discrete element method simulations.
Nonstationarity in the global terrestrial water cycle and its interlinkages in the Anthropocene
Authors: Nie Wanshu , Kumar Sujay V. , Getirana Augusto , Zhao Long , Wrzesien Melissa L. , Konapala Goutam , Ahmad Shahryar Khalique , Locke Kim A. , Holmes Thomas R. , Loomis Bryant D. , Rodell Matthew
Published: October 2024

Climate change and human activities alter the global freshwater cycle, causing nonstationary processes as its distribution shifting over time, yet a comprehensive understanding of these changes remains elusive. Here, we develop a remote sensing–informed terrestrial reanalysis and assess the nonstationarity of and interconnections among global water cycle components from 2003 to 2020. We highlight 20 hotspot regions where terrestrial water storage exhibits strong nonstationarity, impacting 35% of the global population and 45% of the area covered by irrigated agriculture. Emerging long-term trends dominate the most often (48.2%), followed by seasonal shifts (32.8%) and changes in extremes (19%). Notably, in mid-latitudes, this encompasses 34% of Asia and 27% of North America. The patterns of nonstationarity and their dominant types differ across other water cycle components, including precipitation, evapotranspiration, runoff, and gross primary production. These differences also manifest uniquely across hotspot regions, illustrating the intricate ways in which each component responds to climate change and human water management. Our findings emphasize the importance of considering nonstationarity when assessing water cycle information toward the development of strategies for sustainable water resource usage, enhancing resilience to extreme events, and effectively addressing other challenges associated with climate change.
On the role of fiducial structures in minisuperspace reduction and quantum fluctuations in LQC
Authors: Mele Fabio M , Münch Johannes
Published: October 2024

In spatially non-compact homogeneous minisuperpace models, spatial integrals in the Hamiltonian and symplectic form must be regularised by confining them to a finite volume Vo
, known as the fiducial cell. As this restriction is unnecessary in the complete field theory before homogeneous reduction, the physical significance of the fiducial cell has been largely debated, especially in the context of (loop) quantum cosmology. Understanding the role of Vo
is in turn essential for assessing the minisuperspace description’s validity and its connection to the full theory. In this work we present a systematic procedure for the field theory reduction to spatially homogeneous and isotropic minisuperspaces within the canonical framework and apply it to both a massive scalar field theory and gravity. Our strategy consists in implementing spatial homogeneity via second-class constraints for the discrete field modes over a partitioning of the spatial slice into countably many disjoint cells. The reduced theory’s canonical structure is then given by the corresponding Dirac bracket. Importantly, the latter can only be defined on a finite number of cells homogeneously patched together. This identifies a finite region, the fiducial cell, whose physical size acquires then a precise meaning already at the classical level as the scale over which homogeneity is imposed. Additionally, the procedure allows us to track the information lost during homogeneous reduction and how the error depends on Vo
. We then move to the quantisation of the classically reduced theories, focusing in particular on the relation between the theories for different Vo
, and study the implications for statistical moments, quantum fluctuations, and semiclassical states. In the case of a quantum scalar field, a subsector of the full quantum field theory where the results from the ‘first reduced, then quantised’ approach can be reproduced is identified and the conditions for this to be a good approximation are also determined.
Magnetic order in nanogranular iron germanium (Fe0.53Ge0.47) films
Authors: Zielinski Ruthi , Nguyen Nhat , Herrington Bryce , Tarkian Amir , Taha Omar , Chin Wai Kiat , Mahmood Ather , Chen Xiaoqian , Klewe Christoph , Shafer Padraic , Ciston Jim , Ashby Paul , Mazzoli Claudio , Streubel Robert
Published: October 2024

We study the effect of strain on the magnetic properties and magnetization configurations in nanogranular Fe
x
Ge

1
−
x

films (

x
=
0.53
±
0.05

) with and without B20 FeGe nanocrystals surrounded by an amorphous structure. Relaxed films on amorphous silicon nitride membranes reveal a disordered skyrmion phase while films near and on top of a rigid substrate favor ferromagnetism and an anisotropic hybridization of Fe d levels and spin-polarized Ge sp band states. The weakly coupled topological states emerge at room temperature and become more abundant at cryogenic temperatures without showing indications of pinning at defects or confinement to individual grains. These results demonstrate the possibility to control magnetic exchange and topological magnetism by strain and inform magnetoelasticity-mediated voltage control of topological phases in amorphous quantum materials.
From weak- to strong-coupling superconductivity in the AlB2-type solid solution SrGa1−xAlxGe with honeycomb layers
Authors: Walicka Dorota I , Blacque Olivier , Klimczuk Tomasz , von Rohr Fabian O
Published: October 2024

We report on the structure and the superconducting properties of 9-electron 111 compounds with honeycomb layers, namely SrGaGe, SrAlGe, and the SrGa

1
−
x

Al
x
Ge solid solution. By means of single-crystal x-ray diffraction we show that, on one hand, SrGaGe crystallizes into the centrosymmetric P6/mmm space group (a = 4.2555(2) Å, c = 4.7288(2) Å) with statistical disorder in the [GaGe]

6

2
−

honeycomb layers. On the other hand, we confirm that SrAlGe crystallizes in a non-centrosymmetric space group, namely P

6
¯

m2 (a = 4.2942(1) Å, c = 4.7200(2) Å) with fully ordered [AlGe]

6

2
−

honeycomb layers. By using magnetization and specific heat measurements, we show that the superconducting properties of SrGaGe and SrAlGe differ significantly from each other. SrGaGe is a superconductor with a critical temperature of

T

c

= 2.6 K falling into the weak coupling limit, while SrAlGe has a

T
c

= 6.7 K and can be classified in the strong coupling limit. By realizing the SrGa

1
−
x

Al
x
Ge solid solution, we were able to investigate the transition between the different crystal structures as well as the evolution of the electronic properties. We show that the transition from the weak-to strong-coupling superconductivity in this system is likely associated with the disorder-to-order transition of the honeycomb layer, along with the loss of the inversion center in the crystal structure.
Archival records housed at USTUR support radium dial worker dosimetry
Authors: Martinez Nicole E , Jokisch Derek W , Mumma Michael , Tolmachev Sergey Y , Avtandilashvili Maia , Tabatadze George , Leggett Rich , Samuels Caleigh , Golden Ashley , Howard Sara , Dauer L , Boice Jr. John D
Published: October 2024

The American radium dial worker (RDW) cohort of over 3,200 persons is being revisited as part of the Million Person Study (MPS) to include a modern approach to RDW dosimetry. An exceptional source of data and contextualization in this project is an extensive collection of electronic records (requiring 43 gigabytes (GB) of storage) digitized from existing microfilm and microfiche housed at the United States Transuranium and Uranium Registries (USTUR). Although the type, extent, and quality (e.g., legibility) of record(s) varies between individuals, the remarkable occupational, medical and demographic data include in vivo radiation measurements (e.g., radon breath, whole body counts), autopsy results, medical records (including copies of radiographs), interviews over the years, and correspondence. Of particular dosimetric interest are the details of radiation measurements. For example, there are some instances where hand-written and transcribed values are both available, along with notes providing context for why a particular measurement in a time series of measurements was chosen to assign an intake, or if there were concerns about a particular measurement. Born prior to 1935, RDW have nearly all passed away. Thus, the updated dosimetry, especially for the bone, will allow the correlation of lifetime cumulative dose with radiation risk. Here we review typical information available in this collection of historical records, highlighting some interesting finds, and discuss the relevance to current and ongoing work related to updating the dosimetry of the RDW in the Million Person Study, including providing an example of the usefulness of information contained in these records.
MoS2/porous carbon nanofiber heterostructures for efficient evaporation-driven generators
Authors: Ma Haoyu , Zhou Zhicheng , Chen Fengnan , Li Lutao , Wang Ruonan , Ye Yaqi , Li Jiating , Zou Guifu , Zhu Juntong
Published: October 2024

Evaporation power generators (EPGs) based on natural water evaporation can directly convert heat energy from the surrounding environment into electrical energy. Nevertheless, the commercialization of EPGs faces challenges due to the low charge generation and transport efficiency of single material systems, leading to unsatisfactory open-circuit voltages and short-circuit currents. Here, we systematically prepared molybdenum sulfide (MoS2)/porous carbon nanofiber (PCNF) heterogeneous systems by electrospinning and hydrothermal methods. Electron microscope measurements have confirmed the uniform coating of high-crystalline quality MoS2 nanosheets on PCNF fabrics, and the uneven concave–convex surface increased the specific surface area. MoS2 covered PCNF fabrics retained excellent hydrophilicity, which was suitable for absorbing water and keeping the surface wet during long-term evaporation. Moreover, layered MoS2 with rich surface charge improved the charge transfer of the MoS2/PCNF fabrics. As a result, the open-circuit voltage and short-circuit current of the EPGs fabricated with MoS2/PCNF fabrics were enhanced to 0.25 V and 75 μA, respectively, in comparison to those based on PCNF fabrics, which demonstrated that the MoS2 coatings improved the interaction area with water and the charge transfer effect of the EPGs. This heterogeneous combination strategy provides ideas for the preparation of high-performance EPG materials.
Nanoimprinting and backside ultraviolet lithography for fabricating metal nanostructures with higher aspect ratio
Authors: Ding Yu-Chun , Lee Yung-Chun
Published: October 2024

This paper introduces an innovative approach to increasing the aspect ratio of metal nanostructures fabricated using nanoimprint lithography (NIL). Although conventional NIL and metal lift-off processes can fabricate metal nanostructures, the achievable aspect ratio is often limited by the inherent constraints of NIL. In this study, we demonstrate that for an ultraviolet (UV) transparent substrate, metal nanostructures patterned via NIL can serve as a photomask. A negative-tone photoresist (PR) layer was then deposited on top of the patterned metal nanostructures. By illuminating the substrate from the backside with UV light and subsequently developing the PR, PR structures complementary and self-aligned to the metal layer were obtained. This enabled a second round of metal deposition and lift-off, thereby increasing the height of the metal structures and enhancing the aspect ratio. Experimentally, we demonstrated that this method can improve the aspect ratio from less than 1.0 to as high as 2.1. This paper also addresses the further developments and potential applications of this technique.
High performance and nearly wake-up free Hf0.5Zr0.5O2 ferroelectric capacitor realized by middle layer strategy with BEOL compatibility
Authors: Liu Yin-Chi , Xie Gen-Ran , Yang Ji-Ning , Zhang Hao , Golosov Dmitriy Anatolyevich , Gu Chenjie , Zhu Bao , Wu Xiaohan , Lu Hong-Liang , Ding Shi-Jin , Liu Wenjun
Published: October 2024

Hf0.5Zr0.5O2 (HZO) has drawn great attention owing to its excellent ferroelectricity, sub-10 nm scalability, and CMOS compatibility. With regard to increasingly restrict thermal budget and power consumption, conventional HZO films need further optimization to meet these demands. Here, we propose a middle layer (ML) strategy aiming to enhance ferroelectricity and inhibit wake-up effect of ferroelectric (FE) capacitors compatible with back-end of line under the low operating electric field. ZrO2, HfO2, and Al2O3 were integrated into HZO film as different MLs. Among them, the device with ZrO2 ML achieves the excellent double remnant polarization (2P
r) of 41.7 μC cm−2 under the operating electric field of 2 MV cm–1. Moreover, ultralow wake-up ratios of around 0.08 and 0.05 were observed under 2 MV cm–1 and 3 MV cm–1, respectively. Additionally, the FE capacitor with ZrO2 ML demonstrated an enhanced reliability characterizations, including a stable 2P
r of 40.7 μC cm–2 after 4.3 × 109 cycles. This work provides the perspective to optimize both the ferroelectricity and reliability, while maintains the ultralow wake-up ratio in HfO2-based FE through ML engineering.
Photoinduced modulation and the effect of CNT loading on field effect transistor characteristics of CNT/ZnO/PVDF composite
Authors: Bisht Bhanu Prakash , Toutam Vijaykumar , Dhakate Sanjay R
Published: October 2024

Carbon nanotube (CNT)/ZnO/ polyvinylidene fluoride (PVDF) polymer composite phototransistor is studied for the effect of CNT loading and the photoinduced modulation on its transfer characteristics. XRD study shows that the induced strain in the composite is due to the addition of CNT to the ZnO/PVDF composite. The percentage of β-phase present in PVDF is estimated through Raman spectroscopy and the composite’s spectral response is determined by UV-Vis absorbance spectroscopy. From the DC electrical conductivity study it is found that the percolation threshold for the composites is obtained for 0.3 wt% of CNT, and 0.44 wt % of CNT loading makes the composite conductive. On adding 1 wt% of CNT, the electrical conductivity of the ZnO/PVDF composite increases 40 times (∼0.2 μS m−1). The temperature-dependent DC conductivity shows that the conductivity of the composites changes from variable range hopping to band conductance upon an increase in CNT loading above the percolation threshold and exhibits a negative temperature coefficient. Two terminal photoconductivity studies are done to understand the photo enhancement and sensitivity of all the devices. PE hysteresis studies show that the polarization of the composites increases drastically from 0.05 μC cm−2 below the percolation threshold to 10–30 μC cm−2 above the percolation threshold of CNT in the composite. To study the effect of interfacial polarization on photoconductivity, the composite is studied in a three-terminal device format using SiO2 as a gate dielectric. A band diagram analysis of the oxide-composite and CNT/ZnO interface is done to understand the mechanism behind the photoinduced field effect on transfer characteristics and the effect of CNT loading. The switching behavior and decay time under UV illumination are studied to understand the effect of CNT loading and photoinduced polarization. The persistent photoconductivity decreases and the charge collection efficiency of the FET increases as the CNT loading increases.
Tunable photo-response in the visible to NIR spectrum range of Germanium-based junctionless nanowire transistor
Authors: Sharma Vikash , Kumar Nitish , Sharma Sumit , Singh Pushpapraj , Gupta Ankur , Das Samaresh
Published: October 2024

In this paper, the phototransistor behavior is investigated in the germanium-on-insulator (GeOI)-based junctionless nanowire (JL-NW) transistor under various light conditions. High responsivity and photosensitivity are attributed in the fully depleted regime within the visible and near-infrared bands. The impact of light is also investigated in detail on the electronic and transfer characteristics such as energy bandgap, carrier distribution, electrostatic potential, electric field, generation and recombination rates. Further, the channel doping and thickness are tuned to optimize the optical responsivity. The significant tunability of responsivity is observed with increasing channel thickness. The device exhibits fast optical switching performance, which is further enhanced at higher input light power. Overall, at the nanoscale dimension, our proposed phototransistor demonstrates better detectivity with a significantly smaller illumination area. Thus, the GeOI-based JL-NW phototransistors can be used for imaging (visible wavelength range) and bioimaging (near-infrared wavelength range) applications in advanced technology nodes.