jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Philipp Huber | Julian Hanusrichter | Paul Freden | Frank Jenau
Source: Eng—Advances in Engineering (article, 2025-08-06)
Field: Materials Science — Materials Chemistry

Advanced and Robust Numerical Framework for Transient Electrohydrodynamic Discharges in Gas Insulation Systems For the precise description of gas physical processes in high-voltage direct current (HVDC) transmission, an advanced and robust numerical framework for the simulation of transient particle densities in the course of corona discharges is developed in this work. The aim is the scalable and consistent modeling of the space charge density under realistic conditions. The core component of the framework is a discontinuous Galerkin method that ensures the conservative properties of the underlying hyperbolic problem. The space charge density at the electrode surface is imposed as a dynamic boundary condition via Lagrange multipliers. To increase the numerical stability and convergence rate, a homotopy approach is also integrated. For the experimental validation, a measurement concept was realised that uses a subtraction method to specifically remove the displacement current component in the signal and thus enables an isolated recording of the transient ion current with superimposed voltage stresses. The experimental results on a small scale agree with the numerical predictions and prove the quality of the model. On this basis, the framework is transferred to hybrid HVDC overhead line systems with a bipolar design. In the event of a fault, significant transient space charge densities can be seen there, especially when superimposed with new types of voltage waveforms. The framework thus provides a reliable contribution to insulation coordination in complex HVDC systems and enables the realistic analysis of electrohydrodynamic coupling effects on an industrial scale. Electrohydrodynamics ; Transient (computer programming) ; Mechanics ; Transient analysis ; Environmental science ; Materials science ; Transient response ; Nuclear engineering ; Computer science ; Physics ; Engineering ; Electrical engineering ; Electric field High voltage insulation and dielectric phenomena ; Aerosol Filtration and Electrostatic Precipitation ; Lightning and Electromagnetic Phenomena
Authors: Wei Yang | Q. Liu | Wei Huang | Xiaozhong Huang | Peisheng Wang | Shuhong Liu | Yong Du
Source: Materials (article, 2025-10-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Interdiffusion and Atomic Mobilities in Rare Earth Alloys: Measurement and Modeling of Dy-Y, Dy-Nd, Sm-Nd, and Sm-Tb Systems Eight diffusion couples were fabricated to systematically investigate the composition-dependent interdiffusion behavior in hcp Dy-Y, Dy-Nd, Sm-Nd, and Sm-Tb binary alloys. The interdiffusion coefficients were determined at two representative temperatures using the Sauer-Freise method based on concentration-distance profiles measured by electron probe microanalysis (EPMA). These experimentally obtained diffusivities, together with available thermodynamic data, were subsequently employed to assess the atomic mobilities of each system by means of the CALTPP (CALculation of Thermo Physical Properties) program within the CALPHAD (CALculation of PHAse Diagrams) framework. The optimized mobility parameters provide a reliable description of the diffusion behavior in all investigated alloys. This reliability is confirmed by the close agreement between the calculated and experimentally measured interdiffusion coefficients, as well as by the strong consistency between the model-predicted and experimental concentration profiles. The present work thus establishes the first set of critically evaluated atomic mobility parameters for these hcp rare-earth binary systems. These results fill an important gap in the kinetic database of rare-earth alloys and lay a robust foundation for future multi-component CALPHAD-based simulations, thereby supporting the design and optimization of advanced rare-earth permanent magnets with improved coercivity and thermal stability. CALPHAD ; Diffusion ; Work (physics) ; Electron probe microanalysis ; Phase (matter) ; Cryostat ; Phase diagram ; Coercivity ; Binary number Magnetic Properties of Alloys ; Rare-earth and actinide compounds ; Magnetic Properties and Applications
Authors: Martín Ortiz Domínguez | Ángel J. Morales Robles | Arturo Cruz Avilés | Jorge Zuno-Silva
Source: Ingenio y Conciencia Boletín Científico de la Escuela Superior Ciudad Sahagún (article, 2025-01-05)
Field: Materials Science — Ceramics and Composites

Estudio de las capas de boro con un nuevo modelo de transferencia de masa Este trabajo de investigación se enfoca en el crecimiento de los recubrimientos Fe2B formadas sobre la superficie del acero 35NiCrMo4 durante el proceso de borurización sólida. La morfología y el grosor de los recubrimientos de boruro se evaluaron mediante Microscopía Electrónica de Barrido (MEB) y microscopía óptica (MO). Se propuso un nuevo modelo matemático de transferencia de masa para determinar los coeficientes de difusión del boro en los recubrimientos de Fe2B. Se identificó la presencia de recubrimientos de boruro con morfología de dientes de sierra, distribuidas uniformemente por la superficie del sustrato. La composición química y los constituyentes de fase de la capa de boruro se examinaron mediante espectroscopia de dispersión de energía de rayos X (EDS) y análisis de difracción de rayos X (XRD). Como resultado de estos análisis, se detectó la presencia de una capa de boruro monofásica (Fe2B). Las pruebas de microdureza indicaron que la superficie de la muestra borurada tenía una dureza media de alrededor de 1900 HV. Se realizaron pruebas de desgaste utilizando el método de pin on disc en condiciones de deslizamiento en seco a temperatura ambiente, para evaluar el coeficiente de fricción (COF) de las muestras boruradas (promedio ≈ 0.35) y no tratadas (0.725), obteniéndose un efecto positivo de aproximadamente 200% del recubrimiento borurado sobre la resistencia al desgaste. El modelo matemático se validó empíricamente para dos condiciones de tratamiento suplementarias para 1223 K durante 3 h y 1273 K durante 1.5 h, donde el error porcentual para ambas condiciones se estimó alrededor de 2.5%. Por último, se realizó un análisis ANOVA donde se consideraron los factores de temperatura y tiempo, el estudio sugiere que los factores tienen un efecto significativo sobre la variable dependiente (u), donde la temperatura (T) contribuye con un 64.68%, el tiempo (t) con un 27.37% y la combinación de ambos factores (T×t) con un 5.13%. Humanities ; Philosophy Advanced ceramic materials synthesis ; Diamond and Carbon-based Materials Research ; Advanced Surface Polishing Techniques
Authors: RongHuan XU | YiMeng ZHAO | Lu WANG | Long ZENG | Jun LI | Neng REN | JianGuo LI | MingXu XIA
Source: Scientia Sinica Technologica (article, 2025-11-04)
Field: Materials Science — Materials Chemistry

In-situ imaging of Al-based alloy solidification under simulated microgravity and geometric confinement 摘要 重力场中凝固组织受熔体对流、溶质分布及铸型几何结构的共同影响。本研究结合空间微重力环境（10-5 g）抑制自然对流的特性，通过自主设计垂直/水平凝固装置，以Al-20wt.%Cu（亚共晶）与Al-20wt.%Ni（过共晶）为研究对象，结合地面同步辐射和微焦点X射线原位成像技术，定量研究重力、模拟微重力与几何结构（渐扩/台阶/圆角过渡）共同作用下的熔体凝固行为。垂直梯度凝固实验表明：无几何特征的亚共晶Al-Cu合金中低密度初生相析出导致高密度Cu溶质沉降，出现显著的轴向偏析，其顶底浓度差扩大近4.5倍（从0.35 wt.%至1.57 wt.%），宏观偏析标准差增加至初始状态的20倍以上。相比之下，过共晶Al-Ni合金中高密度初生Al3Ni相形成凝固骨架，有效抑制了重力偏析，其标准差增加至初始值的1.5倍，证明了宏观偏析被显著抑制。引入几何结构后，Al-Cu合金的偏析行为明显重塑。所有几何样品均在预凝固期形成“中心富Cu-近壁贫Cu”的初始溶质场；随后渐扩结构在其上侧出现局部贫化区，台阶结构则因“拐角涡流”耦合效应诱发了独特的带状负偏析，而圆角过渡通过稳定流场使偏析演化平缓。这一系列差异最终导致中心区域平均Cu含量呈现无几何(22.18 wt.%) > 渐扩(21.29 wt.%) > 台阶 ≈ 圆角(20.70 wt.%) 的排序。而“台阶≈圆角”的相近Cu含量结果源于两种不同的物理路径：圆角稳定全局流场，而台阶重塑局部溶质场。这证实铸型几何通过影响热-流-溶质多场耦合，进而主导宏观偏析形态与幅度。水平凝固（模拟μg，9 °C/mm高温度梯度）下，渐扩结构固液界面倾斜，非渐扩侧生长速率高于渐扩侧；渐扩角度（30°/45°/75°）增大促使柱状晶扇形角扩展，交界处诱发柱状晶-等轴晶转变（CET）；对比重力条件，水平凝固显著促进柱状晶生长。该研究通过分离熔体对流与几何约束的独立作用，理解和利用几何结构影响地面及空间微重力下铝基合金凝固过程，为空间微重力环境下复杂几何约束下的熔体研究提供参考。 Alloy ; Deformation (meteorology) ; Field (mathematics) ; Copper alloy ; Work (physics) Solidification and crystal growth phenomena ; Aluminum Alloy Microstructure Properties ; Microstructure and mechanical properties
Authors: Takamasa Hirai | Toshiaki Morita | Subrata Biswas | Jun Uzuhashi | Takashi Yagi | Yuichiro Yamashita | Varun K. Kushwaha | Fuya Makino | Rajkumar Modak | Yuya Sakuraba | Tadakatsu Ohkubo | Rulei Guo | Bin Xu | Junichiro Shiomi | Daichi Chiba | Ken‐ichi Uchida
Source: Advanced Functional Materials (article, 2025-10-01)
Field: Materials Science — Materials Chemistry

Non‐Equilibrium Magnon Engineering Enabling Significant Thermal Transport Modulation Abstract Thermal conductivity, a fundamental parameter characterizing thermal transport in solids, is typically determined by electron and phonon transport. Although electrical transport properties are material‐specific, recent advance in understanding phonon transport has led to new insights on controlling the thermal conductivity via phonon engineering techniques. Here, an unconventional way of artificially modulating the heat conduction in solids is demonstrated via engineering of magnon transport. Time‐domain thermoreflectance measurements in ferromagnetic metal/insulator junction systems reveal that the thermal conductivity of the ferromagnetic metals and interfacial thermal conductance vary substantially depending on the spatial distribution of non‐equilibrium spin currents. Systematic measurements of the thermal transport properties with changing the boundary conditions for spin currents unveil that magnons significantly modulate the heat conduction by ≈10 W m −1 K −1 even in ferromagnetic metals at room temperature, upsetting the conventional wisdom that the magnon thermal conductivity is very small in metals except at low temperatures. This magnon‐engineered thermal transport offers a new principle and manner for active thermal management. Magnon ; Thermal conductivity ; Thermal conduction ; Phonon ; Ferromagnetism ; Thermal ; Thermal resistance ; Electron Thermal properties of materials ; Advanced Thermoelectric Materials and Devices ; Graphene research and applications
Authors: Bence G. Márkus | Dávid Beke | Lili Vajtai | Andraś Jánossy | Lászlø Forró | Ferenc Simon
Source: Advanced Functional Materials (article, 2025-11-20)
Field: Materials Science — Materials Chemistry

Unprecedented Spin‐Lifetime of Itinerant Electrons in Natural Graphite Crystals Abstract A long spin‐lifetime of electrons is the holy grail of spintronics, a field exploiting the electron angular momentum as an information carrier and storage unit. Previous reports indicated a spin lifetime, τ s near 10 ns at best in graphene‐based devices at low temperatures. The observation of τ s approaching the ultralong 1,000 ns at room temperature in natural graphite crystals is detailed using magnetic resonance spectroscopy. The relaxation time shows a giant anisotropy: the lifetime of spins, polarized perpendicular to the graphite plane, is more than 50 times longer than for the in‐plane polarization. The temperature dependence of τ s proves that diffusion of spins to the crystallite edges, where relaxation occurs, limits the lifetime. This suggests that graphite is an excellent candidate for spintronic applications, seamlessly integrating with emerging 2D van der Waals technologies. Graphite ; Spintronics ; Electron ; van der Waals force ; Spins ; Relaxation (psychology) ; Diffusion ; Magnetic field Graphene research and applications ; 2D Materials and Applications ; Graphite, nuclear technology, radiation studies
Authors: Maurizio Guerra | Maurizio De Molfetta | A. Diligenti | Marco Falconi | Vincenzo Fiano | Chiara Fiori | Donatello Fosco | Lucina Luchetti | Bruno Notarnicola | Pietro Alexander Renzulli | Enrico Sacchi | Nino Tarantino | Marcello Tognacci | Antonella Vecchio
Source: Preprints.org (preprint, 2025-04-29)
Field: Chemistry — Analytical Chemistry

Detection of Methane Emissive ‘Hot Spots’ in Landfills: An Advanced Statistical Method to Process Uav Data The effective management of landfills requires advancements in techniques for rapid data collection and analysis of gas emissions. This work aims to refine methane (CH₄) emission data acquired from landfills by applying a robust geostatistical method to drone-collected measurements. Specifically, we use UAV-mounted laser spectrophotometer technology (TDLAS-UAV) to gather rapid, high-resolution data, which can sometimes be noisy due to atmospheric variations and sensor drift. For data handling, the key innovation is the application of the Local Indicator of Spatial Association (LISA) to compute the p-values for observed clusters of observations (or better, of grouped observations). This approach was applied both on an areal basis and on a linear basis, following the order of data acquisition, and it produced comparable results. Very low p-values are considered indicative of non-random clustering, suggesting the influence of an underlying spatial control factor. These results were subsequently validated through independent flux chamber surveys. This validation confirms the reliability and objectivity of our geostatistical method in improving drone-based methane emission assessments. The research highlights the need to optimize drone flight paths to ensure a uniform spatial distribution of data and reduce edge effects. It notes that many CH₄ flux measurements often yield non-detectable results, suggesting a review of detection limits. Future work should refine UAV flight patterns and data processing, with semi-controlled experiments -using known methane sources- to determine optimal acquisition parameters such as flight height, sampling frequency, grid resolution, and wind influence. Methane ; Process (computing) ; Environmental science ; Hot spot (computer programming) ; Computer science ; Remote sensing ; Chemistry ; Geology ; Computer network Spectroscopy and Chemometric Analyses ; Mineral Processing and Grinding ; Remote-Sensing Image Classification
Authors: Daniel P. Schmidt | Jonas Wawra | Daniel Hensel | M. Brede | Ruben Hühne | P. Gaal
Source: Desy Publications Database (Deutsches Elektronen-Synchrotron DESY) (preprint, 2025-06-05)
Field: Materials Science — Materials Chemistry

How does picosecond structural deformation of (Ba,Sr)TiO$_{3}$ relate to the pyroelectric effect? The pyroelectric effect in ferroelectric thin films is typically composed of different contributions, which are difficult to disentangle. In addition, clamping to the substrate interface plays an important role. We studied epitaxial (Ba,Sr)TiO$_3$ thin films grown on NdScO$_3$ to see if time-resolved measurements can shed more light on the complex interaction. In particular, we compare standard measurements of the pyroelectric coefficient by temperature-dependent hysteresis loops to transient deformation measurements on picosecond timescales in the same material. The advantage of the time-resolved approach lies in its increased sensitivity in thin films compared to that of polarization hysteresis measurements. Whereas a fast thermal expansion of the ferroelectric thin film was observed after femtosecond laser excitation of the intermediate SrRuO$_3$ layer, heat diffusion simulations reveal frustration of the thermal expansion, which might be explained with the charge dynamics at the Schottky barrier formed at the SrRuO$_3$/(Ba,Sr)TiO$_3$. More studies are required to quantitatively assess the individual contributions to the pyroelectric coefficient of the materials used in our layer architecture. Pyroelectricity ; Thin film ; Picosecond ; Ferroelectricity ; Polarization (electrochemistry) ; Clamping ; Hysteresis ; Thermal expansion ; Femtosecond Ferroelectric and Piezoelectric Materials ; Chemical and Physical Properties of Materials ; Electronic and Structural Properties of Oxides
Authors: Nishant Singh | Suhita Nadkarni
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2025-10-21)
Field: Materials Science — Polymers and Plastics

Structural specialization of mossy fiber boutons is necessary for their unique computational functions Abstract Sparsely active granule cells in the dentate gyrus (DG) project onto CA3 pyramidal neurons through mossy fibers (MF), forming a feedforward network that ensures even similar inputs activate distinct and minimally overlapping populations of CA3 neurons. This process, known as pattern separation, is a key computational feature at this synapse. However, such sparse activity and connectivity increase the risk of information loss, as multiple presynaptic inputs are typically required to elicit a postsynaptic action potential. Interestingly, MF synapses exhibit robust short-term plasticity (STP), enabling a dynamic increase in release probability during brief bursts of presynaptic activity. This mechanism ensures that a short, high-frequency burst from a single granule cell can reliably generate a spike in its postsynaptic CA3 target. Unlike other hippocampal synapses, MF boutons are large, with multiple active zones, each coupled to a cluster of voltage-dependent calcium channels (VDCCs). MF boutons also possess a large readily releasable pool of vesicles. The functional consequences of this unusual synaptic design remain largely unexplored. In fact, the MF synapse is often depicted as a synapse with multiple sites, each behaving as an independent transmission line, analogous to several CA3 boutons contacting a single CA1 dendrite. We developed a physiologically realistic spatial model of the MF bouton to investigate how its peculiar structural and functional properties affect synaptic signaling and plasticity. Contrary to earlier assumptions, our computational model revealed, release sites are not independent transmission units. Crosstalk between calcium domains is necessary for the observed strong STP and for the timely activation of CA3 neurons. VDCCs in the MF bouton are only loosely coupled to active zones, and the distance between active zones is relatively large. In addition to the synaptic design and the known role of calbindin-D28k and synaptotagmin-7 in STP, we find that loose coupling of VDCCs to active zones and large inter-AZ distances are crucial. These features keep the basal release probability low, and their combined action is required to generate the facilitation that triggers postsynaptic action potentials in response to bursts filtering out non-informative dentate activity, and provides a strong rationale for the mossy fiber’s synaptic architecture. Postsynaptic potential ; Synapse ; Neurotransmission ; Dentate gyrus ; Hippocampal formation ; Granule cell ; Gating ; Excitatory postsynaptic potential ; Crosstalk Textile materials and evaluations ; Silk-based biomaterials and applications
Authors: Anna Wicher
Source: Sustainable Production Instrumentation and Engineering Sciences (article, 2025-09-08)
Field: Materials Science — Polymers and Plastics

Measurements of moisture diffusion coefficient of wood wool The moisture diffusion coefficient of wood wool was determined using two analytical methods - Crank's initial sorption method and Liu's method. Measurements were carried out for two ranges of relative humidity in the air around the samples (RH ranges from 0% to 45% and from 45% to 90%). Samples of two types of wood wool were analyzed: the first - with a declared thermal conductivity coefficient of 0.038 W/m∙K and the second - with a declared thermal conductivity coefficient of 0.036 W/m∙K. For the materials examined, the value of the moisture diffusion coefficient decreases as the relative humidity increases. Relative humidity ; Moisture ; Wool ; Humidity ; Diffusion ; Thermal conductivity ; Thermal diffusivity Textile materials and evaluations
Authors: Raj K. Vinnakota | Mayra M Schliemann | Shaimum Shahriar
Source: Journal of Physics Photonics (article, 2025-04-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Optoelectronic control of surface plasmon polaritons at metal-doped semiconductor interfaces Abstract We present a metal–semiconductor (M–S) based electro-optic modulator designed for functional plasmonic circuits, utilizing the active control of surface plasmon polaritons (SPPs) at M–S junction interfaces. Through self-consistent multiphysics simulations, including electromagnetic, thermal, and current–voltage ( IV ) characteristics, we estimate bias- and doping concentration-dependent SPP modulation and switching times. This study focuses on germanium-based Schottky contacts and can be extended to other semiconducting materials. We performed parametric analysis using the developed thermo-electro-optic model to identify device parameters and dimensions for enhanced optical confinement and faster operation. The studied device exhibits signal modulation exceeding −28 dB, responsivity greater than −1800 dB V −1 , and switching rates of 8 GHz, suggesting potential data rates above 16 Gbit s −1 . Additionally, frequency response analysis using the numerical model confirms the device’s electrical tunability and predicts a 3 dB bandwidth of up to 4 GHz. These findings highlight the significant potential of Schottky junctions as active components in the development of plasmonic-based integrated circuits. Surface plasmon polariton ; Optoelectronics ; Doping ; Plasmon ; Materials science ; Polariton ; Semiconductor ; Surface plasmon ; Metal ; Localized surface plasmon Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Photonic and Optical Devices
Authors: Jesús A. Hernández Ramos | Edith Flores Vázquez | Eduardo Coronel Guerra | Oscar A. Gómez Vargas | Martín Ortiz Domínguez | Angel Jesus Morales Robles
Source: Ingenio y Conciencia Boletín Científico de la Escuela Superior Ciudad Sahagún (article, 2025-07-11)
Field: Materials Science — Materials Chemistry

Estudio de las capas FeB/Fe2B formadas sobre la superficie de 2 tipos de aceros y caracterizando la superficie generada por SEM y EDS. El presente trabajo realiza de manera simultánea el tratamiento termoquímico de borurado de dos aceros totalmente diferentes; por un lado, se borura un acero grado herramienta como lo es el AISI H13 y por otro, parte de un acero para rodamientos como el 52100. Las temperaturas de los tratamientos para ambos aceros fueron de 850 y 950°C con tiempos de exposición de 4, 6 y 8 horas. Se llevó a cabo la caracterización metalográfica y el análisis por microscopía electrónica de barrido y se determinaron las energías de activación para cada uno y de forma general los resultados sirvieron para llevar a cabo un análisis desde un punto de vista científico (comparación y comportamiento), técnico (optimización de proceso) e industrial (reducción de costos y validación de aplicaciones). Context (archaeology) Metal Alloys Wear and Properties ; Metallurgical and Alloy Processes ; Microstructure and Mechanical Properties of Steels
Authors: Taras Holubets
Source: Preprints.org (preprint, 2025-05-16)
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. Diffusion ; Microwave ; Irradiation ; Microwave irradiation ; Materials science ; Statistical physics ; Mechanics ; Nuclear engineering ; Thermodynamics ; Physics ; Computer science ; Engineering ; Nuclear physics ; Telecommunications Microwave-Assisted Synthesis and Applications ; Material Properties and Applications ; Advanced materials and composites