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SSRN 2025年

作者： Shivakumar, Sashank Luo, Jian Aiiso Yufeng Li Family Department of Chemical and Nano Engineering University of California La Jolla San DiegoCA92093 United States Program in Materials Science and Engineering University of California La Jolla San DiegoCA92093 United States

Refractory compositionally complex alloy (RCCA) NbMoTaW with a well-dispersed compositionally complex carbide (CCC) reinforcing secondary phase is made through high-energy ball milling (HEBM) and ultrafast high-temperature sintering (UHS). Stearic acid is used as a process control agent (PCA) for HEBM and a carbon source to form a controllable fraction (~2-20 vol%) of CCC in-situ via reactive synthesis. Ultrahigh heating rates of ~100 °C/s enable sintering of dense (~93-97 % relative densities) bulk compacts of RCCA-CCA composites at ~1850 °C in ~70 seconds. With the addition of 0.1-0.75 wt% PCA, ultrafast sintering enables the formation of a favorable P m1 subcarbide CCC phase, (Nb0.37Mo0.11Ta0.39W0.13)2C. A thermodynamic model is developed to explain the observed Nb and Ta enrichments in (Nb0.37Mo0.11Ta0.39W0.13)2C. An additional rock-salt monocarbide CCC phase forms with more carbon source addition (1 wt% PCA). The well-dispersed and fine-grained CCC precipitates result in grain size refinement and a corresponding increase in hardness. © 2025, The Authors. All rights reserved.

关键词： Grain refinement

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Development of Flexible Sendust Composite Sheets with Enhanced Magnetic Permeability for Microwave Absorbers and Antennas

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IEEE Transactions on Magnetics 2025年

作者： Whalen, Matthew P. Plouff, David T. Shevchenko, Nicholas B. Mirotznik, Mark Xiao, John Q. University of Delaware Quantum Science and Engineering Program NewarkDE19716 United States University of Delaware Department of Physics and Astronomy NewarkDE19716 United States University of Delaware Center for Composite Materials NewarkDE19716 United States University of Delaware Department of Electrical and Computer Engineering NewarkDE19716 United States

The demand for high-frequency soft magnetic composites with elevated permeability and flexibility is growing for applications in microwave absorbers and magnetodielectric antennas. However, balancing high permeability with mechanical flexibility remains challenging. This study presents flexible Sendust (FeSiAl) composite sheets, fabricated with a hot-pressing technique that aligns flakes within an acrylic rubber and epoxy resin matrix. The alignment significantly enhances relative permeability at high frequencies, achieving single-layer film properties of μr' = 14.8 and μr"= 20.4 at 1 GHz, alongside high saturation magnetization (118 eμg) and high hesitivity (44.7 kΩ m-1), outperforming commonly used materials such as NiZn ferrite. Our method supports customizable thickness without sacrificing permeability, establishing a versatile platform for advanced conformal microwave absorber and antenna applications. © 2025 IEEE.

关键词： Saturation magnetization

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Three-dimensional construction of hyperuniform, nonhyperuniform, and antihyperuniform disordered heterogeneous materials and their transport properties via spectral density functions

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Physical Review E 2025年第3期111卷 035310-035310页

作者： Wenlong Shi Yang Jiao Salvatore Torquato Materials Science and Engineering Arizona State University Tempe Arizona 85287 USA Department of Physics Arizona State University Tempe Arizona 85287 USA Department of Chemistry Princeton University Princeton New Jersey 08544 USA Department of Physics Princeton University Princeton New Jersey 08544 USA Princeton Institute of Materials Princeton University Princeton New Jersey 08544 USA Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA

Rigorous theories connecting physical properties of a heterogeneous material to its microstructure offer a promising avenue to guide the computational material design and optimization. The spectral density function χ̃V(k), which can be obtained experimentally from scattering data, enables accurate determination of various transport and wave propagation characteristics, including the time-dependent diffusion spreadability S(t) and effective dynamic dielectric constant εe for electromagnetic wave propagation. Moreover, χ̃V(k) determines rigorous upper bounds on the fluid permeability K. Given the importance of χ̃V(k), we present here an efficient Fourier-space based computational framework to construct three-dimensional (3D) statistically isotropic two-phase heterogeneous materials corresponding to targeted spectral density functions. In particular, we employ a variety of analytical functional forms for χ̃V(k) that satisfy all known necessary conditions to construct disordered stealthy hyperuniform, standard hyperuniform, nonhyperuniform, and antihyperuniform two-phase heterogeneous material systems at varying phase volume fractions. We show that by tuning the correlations in the system across length scales via the targeted functions, one can generate a rich spectrum of distinct structures within each of the above classes of materials. Importantly, we present the first realization of antihyperuniform two-phase heterogeneous materials in 3D, which are characterized by autocovariance function χV(r) with a power-law tail, resulting in microstructures that contain clusters of dramatically different sizes and morphologies. We also determine the diffusion spreadability S(t) and estimate the fluid permeability K associated with all of the constructed materials directly from the corresponding spectral densities. Although it is well established that the long-time asymptotic scaling behavior of S(t) only depends on the functional form of χ̃V(k), with the stealthy hyperuniform a

关键词： Spectral density

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Characterization of Ureolysis and Microbially Induced Calcium Carbonate Precipitation Under Different Incubation and Reaction Conditions

SSRN

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SSRN 2025年

作者： Joo, Hyun-Woo Fyfe, Matthew H. Verdú, Irene Rahmaninezhad, Seyed Ali Sales, Christopher M. Srubar, Wil V. Hubler, Mija H. Department of Civil Environmental and Architectural Engineering University of Colorado Boulder BoulderCO United States Department of Civil Architectural and Environmental Engineering Drexel University PhiladelphiaPA United States Environmental Department Terracon Consulting Inc. The ColonyTX United States Department of Civil Environmental and Architectural Engineering Materials Science and Engineering Program University of Colorado Boulder BoulderCO United States Department of Biology

This study investigates the ureolysis and microbially induced calcium carbonate precipitation (MICP) characteristics of Sporosarcina pasteurii and Lysinibacillus sphaericus under varying incubation and reaction conditions. A series of batch MICP experiments were conducted to assess the effects of incubation duration and pH, bacterial cell density, and reagent (i.e., urea and calcium ion) concentrations on ureolysis and CaCO3 precipitation characteristics. The findings indicate that both bacteria exhibit higher urease activity after 24 hours of incubation compared to 48 hours, regardless of incubation pH. S. pasteurii exhibits maximum specific urease activity at an alkaline pH (pH 9.0), whereas L. sphaericus reaches peak activity at a neutral pH (pH 7.2). Across six incubation conditions for each bacterium, S. pasteurii exhibits greater sensitivity in specific urease activity, while L. sphaericus maintains a more consistent ureolysis performance. In terms of cell density, a lower OD600 (~0.1) enhances specific urease activity and early-stage mineralization efficiency, whereas a higher OD600 (~1.0) accelerates overall CaCO3 precipitation, enhances terminal-stage mineralization efficiency, and promotes the prolonged presence of vaterite. High reagent concentrations (1.0 and 1.5 M) enhance specific urease activity and CaCO3 precipitation rates and lead to over 93% of vaterite formation, while low reagent concentration (0.3 M) favors calcite-dominant precipitation over time. These findings provide insights into evaluating and optimizing MICP performance under varying incubation and reaction conditions. © 2025, The Authors. All rights reserved.

关键词： Carbonation

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Bioactivity and cytotoxicity of LiF-modified bioactive glass ceramics for bone regeneration

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Ceramics International 2025年

作者： Selli, Neslihan Tamsü Başaran, Neslihan Kesmez, Ömer Yavaş, Adem Demir, Feride Ertürk, A. Tamer Department of Materials Science and Engineering Gebze Technical University Kocaeli Gebze41400 Turkey Department of Chemistry Faculty of Science Akdeniz University Antalya07058 Turkey Food Technology Program Food Processing Department Çine Vocational School Aydin Adnan Menderes University Aydin Turkey Agricultural Biotechnology and Food Safety Research and Application Center Aydin Adnan Menderes University Aydin Turkey Mechanical Engineering Department Kocaeli University Umuttepe Campus Kocaeli Izmit41001 Turkey

Bioactive glasses and glass-ceramics have drawn significant attention due to their excellent bone-bonding capabilities and biocompatibility. This study investigates the effects of lithium fluoride (LiF) addition on the microstructure, mechanical properties, and biocompatibility of novel bioactive glass compositions. Glasses with varying LiF contents (1, 2, and 3 wt%) were synthesized using the melt-quenching method and subsequently heat-treated to obtain bioactive glass-ceramics. X-ray diffraction (XRD) analysis revealed an increase in the intensity of hydroxyapatite, fluorapatite, and diopside phases with increasing LiF content, suggesting enhanced crystallization. Vickers hardness measurements showed a significant improvement, with the highest hardness (730 MPa) observed in the K3 composition. Scanning Electron Microscopy (SEM) was used to examine the microstructural morphology, while Energy-Dispersive X-ray Spectroscopy (EDX) was employed to analyze the elemental composition of the samples. Furthermore, in vitro bioactivity assessments in simulated body fluid (SBF) confirmed the apatite-forming ability of all compositions. Cytotoxicity evaluations demonstrated enhanced cell viability in LiF-containing compositions, with K3 exhibiting the highest biocompatibility. The findings suggest that LiF addition optimizes crystallization, mechanical performance, and biocompatibility, making these modified bioactive glass-ceramics promising candidates for biomedical applications. © 2025

关键词： Energy dispersive spectroscopy

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Impact of Quantum Well Thickness on Efficiency Loss in InGaN/GaN LEDs: Challenges for Thin-Well Designs

arXiv

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arXiv 2025年

作者： Li, Xuefeng Pant, Nick Rahman, Sheikh Ifatur Armitage, Rob Rajan, Siddharth Kioupakis, Emmanouil Feezell, Daniel University of New Mexico AlbuquerqueNM87106 United States Department of Materials Science & Engineering University of Michigan Ann ArborMI48109 United States Applied Physics Program University of Michigan Ann ArborMI48109 United States Department of Electrical and Computer Engineering The Ohio State University ColumbusOH43210 United States Lumileds LLC San JoseCA95131 United States Department of Materials Science and Engineering The Ohio State University ColumbusOH43210 United States

We investigate the impact of quantum well (QW) thickness on efficiency loss in c-plane InGaN/GaN LEDs using a small-signal electroluminescence (SSEL) technique. Multiple mechanisms related to efficiency loss are independently examined, including injection efficiency, carrier density vs. current density relationship, phase space filling (PSF), quantum confined stark effect (QCSE), and Coulomb enhancement. An optimal QW thickness of around 2.7 nm in these InGaN/GaN LEDs was determined for quantum wells having constant In composition. Despite better control of deep-level defects and lower carrier density at a given current density, LEDs with thin QWs still suffer from an imbalance of enhancement effects on the radiative and intrinsic Auger-Meitner recombination coefficients. The imbalance of enhancement effects results in a decline in internal quantum efficiency (IQE) and radiative efficiency with decreasing QW thickness at low current density in LEDs with QW thicknesses below 2.7 nm. We also investigate how LED modulation bandwidth varies with quantum well thickness, identifying the key trends and their implications for device performance. Copyright © 2025, The Authors. All rights reserved.

关键词： Semiconductor quantum wells

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Correlation versus dissipation in a non-Hermitian Anderson impurity model

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Physical Review B 2025年第12期111卷 125157-125157页

作者： Kazuki Yamamoto Masaya Nakagawa Norio Kawakami Department of Physics Tokyo Institute of Technology Meguro Tokyo 152-8551 Japan Department of Physics University of Tokyo Hongo Tokyo 113-0033 Japan Fundamental Quantum Science Program TRIP Headquarters RIKEN Wako 351-0198 Japan Department of Physics Ritsumeikan University Kusatsu Shiga 525-8577 Japan Department of Materials Engineering Science Osaka University Toyonaka Osaka 560-8531 Japan

We analyze the competition between strong correlations and dissipation in quantum impurity systems from the Kondo regime to the valence fluctuation regime by developing a slave-boson theory for a non-Hermitian Anderson impurity model with one-body loss. Notably, in the non-Hermitian Kondo regime, strong correlations qualitatively change the nature of dissipation through renormalization effects, where the effective one-body loss is suppressed and emergent many-body dissipation characterized by the complex-valued hybridization is generated. We unveil the mechanism of a dissipative quantum phase transition of the Kondo state on the basis of this renormalization effect, which counterintuitively enhances the lifetime of the impurity against loss. We also find a crossover from the non-Hermitian Kondo regime to the valence fluctuation regime dominated by one-body dissipation. Our results can be tested in a wide variety of setups such as quantum dots coupled to electronic leads and quantum point contacts in ultracold Fermi gases.

关键词： Bosons

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Thermoelectrically Elevated Hydrogel Evaporation for Personal Cooling under Extreme Heat

arXiv

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arXiv 2025年

作者： Pei, Yu Feng, Tianshi Chambers, Robert Cai, Shengqiang Chen, Renkun Department of Mechanical and Aerospace Engineering University of California San Diego 9500 Gilman Drive La Jolla CA92093 United States Materials Science and Engineering Program University of California San Diego 9500 Gilman Drive La Jolla CA92093 United States

Extreme heat events with wet-bulb temperatures (WBT) above 35°C pose serious risks to human survival, and conventional hydrogel evaporative cooling alone may not provide sufficient relief as it must be maintained at a sufficiently high temperature to achieve effective evaporation in hot, humid conditions. This study integrates thermoelectric devices (TEDs) with hydrogels to create an effective personal cooling solution. TEDs pump heat away from the skin to maintain comfort while simultaneously increasing the hydrogel’s temperature to enhance evaporation. This hybrid system outperforms TEDs or hydrogel alone in extreme conditions (temperature up to 55°C and relative humidity up to 88%, with WBT > 35°C) and can operate for over six hours with a manageable hydrogel and battery weight. The active temperature control of TEDs allows adaptation to changing thermal loads and environments. These results demonstrate the potential of hybrid evaporative and thermoelectric cooling as an efficient, adaptable, and sustainable personal cooling solution to combat extreme heat. Copyright © 2025, The Authors. All rights reserved.

关键词： Evaporative cooling systems

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CREASE-2D Analysis of Small Angle X-ray Scattering Data from Supramolecular Dipeptide Systems

arXiv

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arXiv 2025年

作者： Gupta, Nitant Akepati, Sri V.V.R. Bianco, Simona Shah, Jay Adams, Dave J. Jayaraman, Arthi Department of Chemical and Biomolecular Engineering University of Delaware NewarkDE19716 United States Data Science Program University of Delaware NewarkDE19716 United States School of Chemistry University of Glasgow GlasgowG12 8QQ United Kingdom Department of Materials Science and Engineering University of Delaware NewarkDE19716 United States

In this paper, we extend a recently developed machine-learning (ML) based CREASE-2D method to analyze the entire two-dimensional (2D) scattering pattern obtained from small angle X-ray scattering measurements of supramolecular dipeptide micellar systems. Traditional analysis of such scattering data would involve use of approximate or incorrect analytical models to fit to azimuthally-averaged 1D scattering patterns that can miss the anisotropic arrangements. Analysis of the 2D scattering profiles of such micellar solutions using CREASE-2D allows us to understand both isotropic and anisotropic structural arrangements that are present in these systems of assembled dipeptides in water and in the presence of added solvents/salts. CREASE-2D outputs distributions of relevant structural features including ones that cannot be identified with existing analytical models (e.g., assembled tubes’ cross-sectional eccentricity, tortuosity, orientational order). The representative three-dimensional (3D) real-space structures for the optimized values of these structural features further facilitate visualization of the structures. Through this detailed interpretation of these 2D SAXS profiles we are able to characterize the shapes of the assembled tube structures as a function of dipeptide chemistry, solution conditions with varying salts and solvents, and relative concentrations of all components. This paper demonstrates how CREASE-2D analysis of entire SAXS profiles can provide an unprecedented level of understanding of structural arrangements which has not been possible through traditional analytical model fits to the 1D SAXS data. © 2025, CC BY-NC-SA.

关键词： X ray scattering

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A Rapid Manual Solid Phase Peptide Synthesis Method for High-Throughput Peptide Production

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Journal of Biomedical materials Research - Part A 2025年第5期113卷 e37922页

作者： Overby, Clyde Abraham, Brittany Adjei-Sowah, Emmanuella March, Alyson Ling, Kevin Basu, Sayantani Benoit, Danielle S. W. Department of Biomedical Engineering University of Rochester RochesterNY United States Center for Musculoskeletal Research University of Rochester RochesterNY United States Department of Chemical Engineering University of Rochester RochesterNY United States Materials Science Program University of Rochester RochesterNY United States Department of Bioengineering Knight Campus for Accelerating Scientific Impact University of Oregon EugeneOR United States

Solid phase peptide synthesis (SPPS) techniques are critical for developing and using peptides in various biomedical applications. However, typical synthesis routes used in SPPS are either resource-intensive (e.g., with automated synthesis or commercial services) or time-consuming (e.g., with manual benchtop synthesis). Here, a rapid manual synthesis method was developed to produce up to 8 peptides with fast cycle times simultaneously. Peptides synthesized manually were of equivalent or superior quality to those produced by in-house microwave-assisted automated peptide synthesis, with higher average crude purity of 70% compared to 50%. The method significantly reduced synthesis time, enabling the parallel coupling of up to 8 amino acids simultaneously in 15–20 min, as opposed to traditional benchtop peptide synthesis, which requires 80–150 min per amino acid. This approach offers an intermediate throughput between milligram-scale libraries and gram-scale single peptide synthesis, enabling rapid iteration for novel peptide designs without the need for expensive automated systems. As a result, peptide modifications, including incorporation of unnatural amino acids, can be explored, accelerating the development of peptides for a wide range of applications. © 2025 The Author(s). Journal of Biomedical materials Research Part A published by Wiley Periodicals LLC.

关键词： Medical applications

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