jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sultan Z. Mahmud | Hye‐Young Heo
Source: Magnetic Resonance in Medicine (article, 2025-04-14)
Field: Materials Science — Materials Chemistry

When CEST meets diffusion: Multi‐echo diffusion‐encoded <scp>CEST</scp> (<scp>dCEST</scp>) <scp>MRI</scp> to measure intracellular and extracellular <scp>CEST</scp> signal distributions The dCEST imaging technique provides valuable insight into the source of signals in conventional CEST MRI, offering potential utility for clinical applications. Extracellular ; Intracellular ; Chemistry ; Extracellular fluid ; Magnetization transfer ; Nuclear magnetic resonance ; Biophysics ; Analytical Chemistry (journal) ; Magnetic resonance imaging ; Biochemistry ; Chromatography ; Biology ; Medicine ; Physics Lanthanide and Transition Metal Complexes ; MRI in cancer diagnosis ; Advanced MRI Techniques and Applications
Authors: David Kniep | M. Rudolphi | Klaus Ohla | Andreas Frehn | Mathias C. Galetz
Source: npj Materials Degradation (article, 2025-05-19)
Field: Materials Science — Metals and Alloys

Hydrogen diffusivity, solubility, and embrittlement of high-strength copper alloys in comparison to stainless steel Abstract The usage of high-strength materials in hydrogen-containing atmospheres is a particular challenge. High-strength copper alloys, which have not been extensively studied, may offer significant potential. In this study, the hydrogen solubility, diffusivity, and embrittlement of two high-strength copper-based alloys, Alloy 25 HT and PerforMet AT, are investigated compared to austenitic stainless steel 316 L. Across all charging conditions, the steel 316 L absorbed multiple orders of magnitude more hydrogen than the copper alloys. Permeation tests reveal effective diffusion coefficients of 1.7 × 10 − 13 m²/s for Alloy 25 HT and 3.0 × 10 −14 m²/s for PerforMet AT at 60 °C, respectively. Results of charged tensile specimens in slow strain rate tests indicated a negligible reduction of strain for Alloy 25 HT and a minor reduction to 83.5% of the strain of the uncharged PerforMet AT, suggesting a low susceptibility to hydrogen embrittlement under these tested conditions. Materials science ; Hydrogen embrittlement ; Embrittlement ; Metallurgy ; Copper ; Thermal diffusivity ; Hydrogen ; Solubility ; Chemistry ; Thermodynamics ; Corrosion Hydrogen embrittlement and corrosion behaviors in metals ; Corrosion Behavior and Inhibition ; Microstructure and Mechanical Properties of Steels
Authors: Jian Yao | Xueyan Guo
Source: Applied Sciences (article, 2025-08-22)
Field: Materials Science — Materials Chemistry

Numerical Analyses of the Influences of Connector Structures on the Performance of Flat-Tube SOFC This study investigates how three flat-tube connector structures—conventional, ribbed flat-tube, and flange-connected—affect solid oxide fuel cell (SOFC) performance. The analysis employs a multi-physics modeling approach to examine the coupled effects of flow fields, gas species transfer, electrochemical reaction, and solid–liquid heat transfer. Results indicate that, under specific conditions, adding internal connector structures can enhance gas transport within the cell, leading to improvements in current density and output power. The flange-connected structure SOFC demonstrated superior output performance, particularly at a flange length of 30 mm, at which it achieved a 4.13% increase in power density compared to the conventional flat-tube SOFC and promoted a more uniform temperature distribution, effectively alleviating uneven temperature distribution inside the cell. Cable gland ; Tube (container) ; Materials science ; Mechanical engineering ; Engineering ; Composite material Advancements in Solid Oxide Fuel Cells ; Magnetic and transport properties of perovskites and related materials ; Electronic and Structural Properties of Oxides
Authors: Biljana Z. Maksimović | Andrijana Žekić | Branislava M. Vučetić | Milica M. Milojević | Vladislav Jovanov | M.M. Mitrović | Dragana Malivuk Gak
Source: ACS Omega (article, 2025-01-15)
Field: Materials Science — Materials Chemistry

Study of the Effect of Supersaturation Changes on the Growth of {100} KDP Crystal Faces This study investigates the growth of {100} KDP crystal faces under varying supersaturation conditions of 6.2-14.7%. The findings indicate that the positions of growth rate maxima differ between experiments where supersaturation increases or decreases, with higher rates associated with decreasing supersaturation. Surface analysis via SEM and AFM revealed that higher supersaturation resulted in greater roughness. The growth rate on supersaturation dependence <i>R</i>(σ) for both types of experiments was best described by parabolic and power law models, indicating spiral growth. A significant percentage of crystal faces exhibited an exponent <i>n</i> > 2, suggesting the relevance of the multiple nucleation model. Additional analysis excluded the suggested model in favor of the polynuclear model. No significant difference was found between the arithmetic means of <i>n</i> values for both types of experiments, suggesting that for the investigated supersaturation range, the growth mechanism of {100} KDP crystal faces is independent of growth history. Supersaturation ; Crystal (programming language) ; Materials science ; Crystal growth ; Crystallography ; Chemical physics ; Chemistry ; Computer science ; Thermodynamics ; Physics Crystallization and Solubility Studies ; Nonlinear Optical Materials Research ; X-ray Diffraction in Crystallography
Authors: Reem Hasaballah Alhasani | Hadba Hussain | Mohammed A. Alkhamisah | Abdulrhman Faraj M Hiazaa | Abdullah Alharbi
Source: Materials (article, 2025-10-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Advances in High-Voltage Power Electronics Using Ga2O3-Based HEMT: Modeling Gallium oxide (Ga<sub>2</sub>O<sub>3</sub>) is a promising ultra-wide-bandgap (UWBG) material with exceptional transport properties, including a large breakdown voltage, making it ideal for high-voltage power device applications. Recently, Ga<sub>2</sub>O<sub>3</sub> has gained significant attention as a next-generation material for electronic device fabrication aimed at advancing power electronics. In this paper, we investigate the effect of a Ga<sub>2</sub>O<sub>3</sub> buffer layer on a GaN-based high electron mobility transistor (HEMT), focusing on output I-V characteristics and surface charge effects. Furthermore, we explore an advanced approach to enhance HEMT performance by utilizing polarization-induced two-dimensional electron gas (2DEG), as an alternative to conventional doping methods. A III-N/Ga<sub>2</sub>O<sub>3</sub> heterostructure is proposed as a distinctive electrical property and a cost-effective UWBG solution. To evaluate the associated effects, we simulate a two-dimensional (2D) Ga<sub>2</sub>O<sub>3</sub>/GaN HEMT structure incorporating surface charge models. Our results confirm that 2DEG formation near the surface creates a conductive channel due to polarization-induced dipoles at the interface. The simulations also show a negative shift in the threshold voltage, a condition typically unattainable without oxidation layers or doping. Finally, we analyze the potential of AlGaN/Ga<sub>2</sub>O<sub>3</sub>-based HEMTs for future power electronic applications. High-electron-mobility transistor ; Transistor ; Power semiconductor device ; Power electronics ; Fabrication ; Electronics ; Doping ; Heterojunction ; Power (physics) Ga2O3 and related materials ; Magnesium Oxide Properties and Applications
Authors: G. V. Garkushin | А. С. Савиных | С. В. Разоренов | И. Г. Бродова | D. Yu. Rasposienko | D. I. Devyaterikov | Peter Panfilov
Source: Journal of Applied Physics (article, 2025-01-13)
Field: Materials Science — Materials Chemistry

Shock compression of [101¯0]-axis zinc single crystal Zinc single crystals have been shocked by planar impact along the [101¯0] axis as well as in the off-axis direction. The evolution of compression waves has been analyzed from the free surface velocity profiles of zinc single crystal samples. A slip on the primary system is activated by impact loading in directions making angles of θ = 17°–64° with respect to the [101¯0] axis. The phenomenon of the formation of two plastic compression waves propagating at different velocities is observed in samples oriented at angles of 53° and 64°. The spall fracture of single crystal zinc samples oriented in different directions has been measured. It is shown that the highest value of spall strength is recorded along the highly symmetric axis of the crystal. The experimental results presented are consistent with the data published in the scientific literature on beryllium and magnesium and confirm the important role of crystalline anisotropy in the process of inelastic deformation of single crystals. Beryllium ; Anisotropy ; Single crystal ; Materials science ; Zinc ; Shock wave ; Spall ; Compression (physics) ; Crystal (programming language) ; Crystal twinning ; Slip (aerodynamics) ; Shock (circulatory) ; Composite material ; Crystallography ; Mechanics ; Optics ; Metallurgy ; Chemistry ; Physics ; Thermodynamics High-Velocity Impact and Material Behavior ; Energetic Materials and Combustion ; Microstructure and mechanical properties
Authors: Nguyen Huy Tuan | Le Thi Thao Nhi
Source: Discrete and Continuous Dynamical Systems - B (article, 2025-08-26)
Field: Materials Science — Materials Chemistry

On the time-fractional Cahn-Hilliard equation: Well-posedness, global solutions, and convergence to classical dynamics This paper investigated the Cauchy problem for the time-fractional Cahn–Hilliard equation formulated with the Caputo derivative. By developing sharp estimates for the corresponding Green's functions, we first established the local-in-time existence of mild solutions, which were obtained through an integral formulation of the problem. To address the challenges posed by the nonlocal nature of the fractional derivative, we introduced new weighted function spaces that enabled us to extend these local solutions to a global-in-time framework under suitable smallness conditions on the initial data. Moreover, we rigorously analyzed the asymptotic behavior of the solution and demonstrated that, as the fractional order approached one, the mild solution converged to that of the classical Cahn–Hilliard equation. These results not only clarified the relationship between nonlocal dynamics and traditional phase separation but also suggested that the methods and techniques presented in this paper could be applied to many other models related to the Caputo derivative. Convergence (economics) ; Cahn–Hilliard equation ; Dynamics (music) ; Applied mathematics ; Mathematics ; Mathematical analysis ; Physics ; Economics ; Partial differential equation Solidification and crystal growth phenomena ; Nonlinear Partial Differential Equations ; Fractional Differential Equations Solutions
Authors: Kyuhwe Kang | Abhishek Pathak | Yiwen Song | Husam Walwil | Timothy Mirabito | Nathaniel S. McIlwaine | Mi‐Hee Ji | LeighAnn S. Larkin | Christopher B. Saltonstall | Andrew A. Allerman | Jon-Paul Maria | Joan M. Redwing | Jonathan A. Malen | Alan J. H. McGaughey | Sukwon Choi
Source: Journal of Applied Physics (article, 2025-08-22)
Field: Materials Science — Materials Chemistry

Phonon transport in Al-rich AlxGa1−xN thin films AlxGa1−xN with a high Al composition (x) presents significant potential for advancing next-generation high-power electronic devices. To support the thermal design of AlxGa1−xN-based electronics, the thermal conductivity of AlxGa1−xN thin films was measured as a function of Al composition, temperature, and film thickness using time-domain thermoreflectance and frequency-domain thermoreflectance techniques. The measurement results were interpreted by modeling phonon transport in AlxGa1−xN films using the phonon Boltzmann transport equation. Phonon properties, including frequencies, group velocities, and lifetimes, were calculated using a virtual crystal approximation, with the effects of mass-disorder scattering incorporated via the Tamura model. The measured thermal conductivity of Al0.7Ga0.3N is an order of magnitude lower than those for GaN and AlN, exhibits an increase followed by saturation with temperature, and shows a modest decrease with a reduction in the film thickness. The modeling results agree with the measurement results and reveal that mass-disorder scattering and phonon-boundary scattering are the dominant mechanisms that reduce the thermal conductivity of AlxGa1−xN thin films. Thin film ; Phonon ; Materials science ; Condensed matter physics ; Nanotechnology ; Physics Thermal properties of materials ; GaN-based semiconductor devices and materials ; Advancements in Semiconductor Devices and Circuit Design
Authors: David Crawford | Yi Zeng | Judith Vidal | Jianjun Dong
Source: Physical review. B./Physical review. B (article, 2025-09-02)
Field: Materials Science — Materials Chemistry

Time-domain theory of transient heat conduction in the local limit Ultrafast and nanoscale heat conduction demands a unified theoretical framework that rigorously bridges macroscopic transport equations with microscopic material properties derived from statistical physics. Existing empirical generalizations of Fourier's law often lack a solid microscopic foundation, failing to connect observed non-Fourier behavior with underlying atomic-scale mechanisms. In this work, we present a time-domain theory of transient heat conduction rooted in Zwanzig's statistical theory of irreversible processes. Central to this framework is the time-domain transport function <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mover accent="true"><a:mi>Z</a:mi><a:mo>↔</a:mo></a:mover><a:mrow><a:mo>(</a:mo><a:mi>t</a:mi><a:mo>)</a:mo></a:mrow></a:mrow></a:math> defined through equilibrium time-correlation functions of heat fluxes. This function generalizes the conventional concept of steady-state thermal conductivity, governing the transition of conduction dynamics from onset second sound type wave propagation at finite speeds to diffusion-dominated behavior across broad temporal and spatial scales. Unlike phonon hydrodynamic models that rely on mesoscopic constructs such as phonon drift velocity, our approach provides a quantitative and microscopic description of intrinsic memory effects in transient heat fluxes and applies universally to bulk materials at any temperature or length scale. By integrating atomistic-scale first-principles calculations with continuum-level macroscopic equations, this framework offers a robust foundation for numerical simulations of transient temperature fields. Furthermore, it facilitates the interpretation and design of transient thermal grating experiments using nanometer-scale heat sources and ultrafast laser systems in the extreme ultraviolet and x-ray wavelength ranges, advancing our understanding of heat dissipation dynamics. Transient (computer programming) ; Limit (mathematics) ; Thermal conduction ; Mechanics ; Materials science ; Physics ; Mathematics ; Thermodynamics ; Computer science ; Mathematical analysis Thermal properties of materials ; Heat Transfer and Optimization ; Thermoelastic and Magnetoelastic Phenomena
Authors: Anannya Bhattacharya | Subhrajit Sikdar | Sanatan Chattopadhyay
Source: physica status solidi (a) (article, 2025-02-04)
Field: Materials Science — Materials Chemistry

Analytical Modeling and Design Optimization of High‐Performance ZnO‐Nanowire/CuO‐Thin Film/p<sup>+</sup>‐Si Multi‐Junction Solar Cells In the current work, an optimized design window for the indium tin oxide (ITO)/n‐ZnO‐nanowire (NW)/p‐CuO‐thin film/p + ‐Si multi‐junction solar cells is provided for achieving high power conversion efficiency (PCE). The requisite model has been developed using the drift‐diffusion approach and validated against existing experimental data. The effects of various design parameters are thoroughly investigated and optimized to achieve higher PCE. Initially, by optimizing the lengths of ZnO NWs and the thickness of CuO films, a PCE of 22% is achieved. To enhance the PCE further, ZnO NWs are doped with cobalt (Co) (0–15%), and the CuO thin film is doped with graphene (Gr) (0–10%), independently. The impact of annealing of the top‐ITO layer on PCE has also been studied without any doping. Finally, optimizing the geometric parameters of ZnO‐NW (length of 200 nm), CuO thin film (thickness of 350 nm), doping concentrations of Co (5%) and Gr (5%), and the annealing temperature of ITO (450 °C), PCE of the proposed n‐ZnO‐NW/p‐CuO‐thin film/p + ‐Si multi‐junction solar cell is obtained to be ≈40%. Thus, in this work, a comprehensive set of design parameters for ZnO‐NW/CuO‐thin‐film/Si‐based solar cells is provided to achieve high PCE. Nanowire ; Thin film ; Thin film solar cell ; Optoelectronics ; Materials science ; Solar cell ; Nanotechnology ZnO doping and properties ; Copper-based nanomaterials and applications ; Chalcogenide Semiconductor Thin Films
Authors: Taras Holubets
Source: Preprints.org (preprint, 2025-05-06)
Field: Chemistry — Organic Chemistry

Mathematical Modeling of Mechanical Thermo-Diffusion Processes Under Influence of Microwave Irradiation in this work the methods of applying the spatial averaging method to the description of the diffusion, electrodynamics and mechanical properties of a porous multiphase (composite) wetted medium are considered. the set of physical phenomena and processes in porous wetted materials is described in detail, as well as mathematical or theoretical models are proposed to describe the interaction of moisture, electromagnetic and mechanical fields. for a porous humidified medium, a closed system of equations was obtained, which connects the processes of heat and mass transfer with internal heat sources induced by external microwave electromagnetic radiation and mechanical stresses within the framework of the model of a continuous continuous medium. Microwave irradiation ; Diffusion ; Microwave ; Irradiation ; Materials science ; Nuclear engineering ; Biological system ; Thermodynamics ; Physics ; Computer science ; Engineering ; Nuclear physics ; Telecommunications ; Biology Microwave-Assisted Synthesis and Applications ; Material Properties and Applications ; Advanced materials and composites
Authors: Qingliang Li | Jian Wang | Gang Cheng | Qing Tao
Source: Metals (article, 2025-08-22)
Field: Materials Science — Materials Chemistry

Low-Temperature Tempering to Tailor Microstructure, Mechanical and Contact Fatigue Performance in the Carburized Layer of an Alloy Steel for Heavy-Duty Gears Taking a typical carburized alloy steel for heavy-duty gears as the research object, this work regulates carburizing–quenching and tempering processes to conduct a layer-by-layer analysis of gradient-distributed microstructures and mechanical properties in the carburized layer. The effects of tempering temperature on martensite evolution, mechanical properties, and wear resistance were specifically investigated. Results demonstrate that carburizing–quenching followed by cryogenic treatment generates high-carbon martensite at the surface, progressively transitioning to lath martensite towards the core. Low-temperature tempering promotes fine carbide precipitation, while elevated temperatures cause carbide coarsening. Specimens tempered at 175 °C achieve surface hardness of 800 HV and near-surface compressive yield strength of 2940 MPa. These samples exhibit 13% lower wear mass loss compared to 240 °C tempered counterparts, demonstrating superior wear resistance characterized by relatively flat wear surfaces, uniform contact stress distribution, and reduced cross-sectional plastic deformation zones. Key strengthening mechanisms at lower tempering temperatures involve solution strengthening, dislocation strengthening, and partial precipitation strengthening from carbides. Coherent carbides formed under these conditions impede fatigue dislocation motion via shearing mechanisms to suppress plastic deformation and fatigue crack initiation under contact fatigue stress, thereby enhancing wear performance. Tempering ; Materials science ; Microstructure ; Metallurgy ; Alloy ; Heavy duty ; Layer (electronics) ; Composite material ; Engineering ; Automotive engineering Metal Alloys Wear and Properties ; Microstructure and Mechanical Properties of Steels ; Surface Treatment and Residual Stress
Authors: Christoph Hurm | Maximilian Moser
Source: GAMM-Mitteilungen (article, 2025-05-20)
Field: Materials Science — Materials Chemistry

Nonlocal‐to‐local convergence for a Cahn–Hilliard tumor growth model Abstract We consider a local Cahn–Hilliard‐type model for tumor growth as well as a nonlocal model where, compared to the local system, the Laplacian in the equation for the chemical potential is replaced by a nonlocal operator. The latter is defined as a convolution integral with suitable kernels parametrized by a small parameter. For sufficiently smooth bounded domains in three dimensions, we prove convergence of weak solutions of the nonlocal model toward strong solutions of the local model together with convergence rates with respect to the small parameter. The proof is done via a Gronwall‐type argument and a convergence result with rates for the nonlocal integral operator toward the Laplacian due to Abels and Hurm. Convergence (economics) ; Growth model ; Cahn–Hilliard equation ; Statistical physics ; Applied mathematics ; Mathematics ; Economics ; Mathematical economics ; Physics ; Mathematical analysis ; Macroeconomics Solidification and crystal growth phenomena ; Advanced Mathematical Modeling in Engineering ; Mathematical and Theoretical Epidemiology and Ecology Models
Authors: Sandipan Mohanty | K. M. Ranjith | C. S. Saramgi | Y. Skourski | B. Büchner | H.‐J. Grafe | R. Nath
Source: ArXiv.org (preprint, 2025-02-10)
Field: Chemistry — Inorganic Chemistry

Ground state properties of a spin-$\frac{5}{2}$ frustrated triangular lattice antiferromagnet NH$_{4}$Fe(PO$_{3}$F)$_2$ Structural and magnetic properties of a two-dimensional spin-$\frac{5}{2}$ frustrated triangular lattice antiferromagnet NH$_{4}$Fe(PO$_{3}$F)$_2$ are explored via x-ray diffraction, magnetic susceptibility, high-field magnetization, heat capacity, and $^{31}$P nuclear magnetic resonance experiments on a polycrystalline sample. The compound portrays distorted triangular units of the Fe$^{3+}$ ions with anisotropic bond lengths. The magnetic susceptibility shows a broad maxima around $T^{\rm{max}}_χ\simeq 12$ K, mimicking the short-range antiferromagnetic order of a low-dimensional spin system. The magnetic susceptibility and NMR shift could be modeled assuming the spin-$5/2$ isotropic triangular lattice model and the average value of the exchange coupling is estimated to be $J/k_{\rm B} \simeq 1.7$ K. This value of the exchange coupling is reproduced well from the saturation field of the pulse field data. It shows the onset of a magnetic ordering at $T_{\rm N} \simeq 5.7$ K, setting the frustration ratio of $f = \frac{|θ_{\rm CW}|}{T_{\rm N}} \simeq 5.7$. Such a value of $f$ reflects moderate magnetic frustration in the compound. The d$M$/d$H$ vs $H$ plots of the low temperature magnetic isotherms exhibit a sharp peak at $H_{\rm SF} \simeq 1.45$ T, suggesting a field-induced spin-flop transition and magnetic anisotropy. The rectangular shape of the $^{31}$P NMR spectra below $T_{\rm N}$ unfolds that the ordering is commensurate antiferromagnet type. Three distinct phase regimes are clearly discerned in the $H - T$ phase diagram, redolent of a frustrated magnet with in-plane (XY-type) anisotropy. Antiferromagnetism ; Hexagonal lattice ; Condensed matter physics ; Ground state ; Spin (aerodynamics) ; Lattice (music) ; Frustration ; Physics ; State (computer science) ; Chemistry ; Mathematics ; Quantum mechanics ; Thermodynamics Inorganic Fluorides and Related Compounds ; Magnetism in coordination complexes ; Crystal Structures and Properties