jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Xiaotian Yan | Christos Tserkezis | N. Asger Mortensen | Guy A. E. Vandenbosch | Xuezhi Zheng
Source: arXiv (Cornell University) (preprint, 2023-09-15)
Field: Materials Science — Surfaces, Coatings and Films

A Dedicated Modelling Scheme for Nonclassical Optical Response from the Nanosphere-on-Mirror Structure Within the framework of the T-matrix method, we present a modeling tool that predicts the optical response from the Nanosphere-on-Mirror (NSoM) construct. The nonclassical effects in metals are accounted for by the nonlocal hydrodynamic Drude model (NLHDM) or the surface response model (SRM). Two essential elements in the T-matrix method, i.e., the T-matrix of the sphere and the R matrix accounting for the effects of the mirror, have been fully upgraded to include longitudinal waves for the NLHDM and the augmented interface conditions for the SRM. The proposed tool is quantitatively validated both in the near and the far field by an in-house developed BEM solver for the NLHDM where the gap between the sphere and the mirror is as small as 1 nm. Two physical checks are performed, where the results from the classical local response model are compared with the ones from the NLHDM and the SRM. The observed shifts in resonances and reduced field enhancements in the gap region agree well with previous physical findings. The proposed tool may not only serve as a reference tool for other numerical methods, but also provides an ideal platform for investigating nonclassical optical processes in the NSoM, hence paving a semi-analytical way to understand the extreme optics at very small scales. Solver ; Matrix (chemical analysis) ; Physics ; Field (mathematics) ; Computer science ; Construct (python library) ; Surface (topology) ; Optics ; Mathematics ; Geometry ; Materials science Optical Coatings and Gratings ; Plasmonic and Surface Plasmon Research ; Photonic and Optical Devices
Authors: Amirouche Goumghar
Source: theses.fr (ABES) (article, 2023-01-31)
Field: Materials Science — Polymers and Plastics

Elaboration and study of the dynamic performance of bio-sourced composites with a hybrid flax-glass architecture L'utilisation des matériaux composites renforcés par des fibres végétales ne cesse de croitre dans divers secteurs tels que l'automobile et le packaging. Toutefois, le problème de leur sensibilité à l'humidité freine encore leur utilisation dans des applications exposées à des conditions environnementales extrêmes. Par conséquent, l'hybridation des fibres végétales avec des fibres synthétiques peut constituer une voie prometteuse pour améliorer certaines propriétés des composites à renfort végétal. C'est dans ce contexte que se situe le présent travail doctoral. Il présente une analyse expérimentale du comportement en fatigue par traction--traction et en fatigue par chocs à faible énergie de stratifiés non hybrides et hybrides lin-verre/époxyde. Une investigation de leur durabilité après un vieillissement hydrique jusqu'à la saturation est également présentée. À cette fin, plusieurs plaques des composites non hybrides et hybrides lin-verre/époxyde ont été élaborées par le procédé d'infusion sous vide. Dans un premier temps, nous avons réalisé une caractérisation en traction monotone des composites de l'étude et étudié la cinétique de diffusion de l'humidité au sein de ces matériaux. Les résultats de ces essais montrent que le remplacement de couches de lin par des couches de verre améliore nettement les propriétés mécaniques stratifié lin/époxyde et diminue également sa masse d'eau absorbée à saturation. Ensuite, des essais de fatigue cyclique ont été réalisés sur des éprouvettes composites non vieillies et vieillies. Ces essais de fatigue ont été couplés à la technique de l'émission acoustique afin d'identifier les mécanismes d'endommagement et leur chronologie d'apparition. Pour évaluer l'effet de la charge de fatigue sur la perte de rigidité, les boucles d'hystérésis et le facteur d'amortissement des composites non hybrides et hybrides ont été étudiées. L'analyse des signaux acoustique permet d'identifier trois classes de signaux acoustiques dans tous les composites étudiés. Ces trois classes sont attribuées aux principaux mécanismes d'endommagement comme la fissuration matricielle, la décohésion fibre--matrice et la rupture des fibres. Cette attribution est consolidée par des observations microscopiques obtenues à l'aide d'un microscope électronique à balayage. Enfin, des essais de fatigue par chocs à faible énergie ont été réalisés sur des échantillons composites non vieillis et vieillis. Les résultats obtenus montrent clairement que le composite lin/époxyde absorbe une grande partie de l'énergie d'impact en déformation élastique. Cependant, le stratifié verre/époxyde consomme cette énergie en endommagement et rupture. De plus, le vieillissement hydrique fragilise tous les composites étudiés et diminue leur résistance à la fatigue par chocs. Materials testing ; Fatigue testing ; Stab Natural Fiber Reinforced Composites ; Mechanical Behavior of Composites ; Hygrothermal properties of building materials
Authors: L. H. Fowler-Gerace | Zhiwen Zhou | E.A. Szwed | D. J. Choksy | L. V. Butov
Source: arXiv (Cornell University) (preprint, 2023-07-03)
Field: Materials Science — Materials Chemistry

Transport and localization of indirect excitons in a van der Waals heterostructure Long lifetimes of spatially indirect excitons (IXs), also known as interlayer excitons, allow implementing both quantum exciton systems and long-range exciton transport. Van der Waals heterostructures (HS) composed of atomically thin layers of transition-metal dichalcogenides (TMD) offer the opportunity to explore IXs in moiré superlattices. The moiré IXs in TMD HS form the materials platform for exploring the Bose-Hubbard physics and superfluid and insulating phases in periodic potentials. IX transport in TMD HS was intensively studied and diffusive IX transport with $1/e$ decay distances $d_{1/e}$ up to $\sim 3$ $μ$m was realized. In this work, we present in MoSe$_2$/WSe$_2$ HS the IX long-range transport with $d_{1/e}$ exceeding 100 $μ$m and diverging at the optical excitation resonant to spatially direct excitons. The IX long-range transport vanishes at high temperatures. With increasing IX density, IX localization, then IX long-range transport, and then IX reentrant localization is observed. The results are in qualitative agreement with the Bose-Hubbard theory of bosons in periodic potentials predicting superfluid at $N \sim 1/2$ and insulating at $N \sim 0$ and $N \sim 1$ phases for the number of bosons per site of the periodic potential $N$. Superfluidity ; Exciton ; Boson ; Condensed matter physics ; Physics ; van der Waals force ; Heterojunction ; Superlattice ; Excitation ; Quantum mechanics 2D Materials and Applications ; Graphene research and applications ; Molecular Junctions and Nanostructures
Authors: Qi Xie | Sea On Lee | Nitya Vissamsetti | Sikao Guo | Margaret E. Johnson | Stephen D. Fried
Source: Angewandte Chemie (article, 2023-07-20)
Field: Materials Science — Biomaterials

Secretion‐Catalyzed Assembly of Protein Biomaterials on a Bacterial Membrane Surface Abstract Protein‐based biomaterials have played a key role in tissue engineering, and additional exciting applications as self‐healing materials and sustainable polymers are emerging. Over the past few decades, recombinant expression and production of various fibrous proteins from microbes have been demonstrated; however, the resulting proteins typically must then be purified and processed by humans to form usable fibers and materials. Here, we show that the Gram‐positive bacterium Bacillus subtilis can be programmed to secrete silk through its translocon via an orthogonal signal peptide/peptidase pair. Surprisingly, we discover that this translocation mechanism drives the silk proteins to assemble into fibers spontaneously on the cell surface, in a process we call secretion‐catalyzed assembly (SCA). Secreted silk fibers form self‐healing hydrogels with minimal processing. Alternatively, the fibers retained on the membrane provide a facile route to create engineered living materials from Bacillus cells. This work provides a blueprint to achieve autonomous assembly of protein biomaterials in useful morphologies directly from microbial factories. Secretion ; Bacillus subtilis ; SILK ; Chemistry ; Cell biology ; Secretory protein ; Fibroin ; Translocon ; Nanotechnology ; Protein engineering ; Membrane ; Membrane protein ; Materials science ; Bacteria ; Biochemistry ; Biology ; Enzyme Silk-based biomaterials and applications ; Biochemical and Structural Characterization ; Antimicrobial Peptides and Activities
Authors: Greta Andrini | G. Zanelli | S. Ditalia Tchernij | Emilio Corte | Elena Nieto Hernández | Alessio Verna | Matteo Cocuzza | Ettore Bernardi | Salvatore Virzì | P. Traina | Ivo Pietro Degiovanni | Marco Genovese | P. Olivero | J. Forneris
Source: arXiv (Cornell University) (preprint, 2023-04-20)
Field: Materials Science — Materials Chemistry

Efficient activation of telecom emitters in silicon upon ns pulsed laser annealing The recent demonstration of optically active telecom emitters makes silicon a compelling candidate for solid state quantum photonic platforms. Particularly fabrication of the G center has been demonstrated in carbon-rich silicon upon conventional thermal annealing. However, the high-yield controlled fabrication of these emitters at the wafer-scale still requires the identification of a suitable thermodynamic pathway enabling its activation following ion implantation. Here we demonstrate the efficient activation of G centers in high-purity silicon substrates upon ns pulsed laser annealing. The proposed method enables the non-invasive, localized activation of G centers by the supply of short non-stationary pulses, thus overcoming the limitations of conventional rapid thermal annealing related to the structural metastability of the emitters. A finite-element analysis highlights the strong non-stationarity of the technique, offering radically different defect-engineering capabilities with respect to conventional longer thermal treatments, paving the way to the direct and controlled fabrication of emitters embedded in integrated photonic circuits and waveguides. Fabrication ; Silicon ; Wafer ; Materials science ; Silicon photonics ; Optoelectronics ; Ion implantation ; Photonics ; Annealing (glass) ; Laser ; Metastability ; Nanotechnology ; Hybrid silicon laser ; Ion ; Optics ; Chemistry ; Physics Silicon Nanostructures and Photoluminescence ; Diamond and Carbon-based Materials Research ; Thin-Film Transistor Technologies
Authors: Diego de Quadros Melo | Lucas Fontenele Amorim | André Gadelha de Oliveira | João da Cunha | André Fernando de Oliveira | Carla Bastos Vidal | Ronaldo Ferreira do Nascimento
Source: Journal of the Brazilian Chemical Society (article, 2023-01-01)
Field: Materials Science — Biomaterials

Use of High-Efficiency Lignocellulose-Based Materials for Toxic Ions Removal: Impact of Surface Chemistry and Mathematical Modeling Low-cost adsorbents promote the valorization of locally sourced waste materials and are still a significant challenge for removing toxic metal ions from industrial effluents. In this sense, Castor (Ricinus communis L.) stalks (CS) were activated with an alkaline solution and tested as an adsorbent to remove nickel, copper, cadmium, and lead ions. A 24-1 factorial design was carried out and showed a correlation and influence of the variables, such as pH, adsorbent mass, agitation rate, and initial concentration in the adsorption process. The adsorbents in their natural, activated, and saturated states were characterized. After activation, X-ray diffraction results revealed a change from cellulose I to cellulose II. The X-ray fluorescence showed that the ion exchange adsorption mechanism occurred. For the kinetic adsorption studies, the equilibrium time was reached up to 15 min. Different isotherm models described the adsorption process, with the Sips model providing the best fit to the experimental data. Five cycles of sorption/desorption using 0.1 mol L-1 HCl elution were carried out with a minimal loss in sorption capacity and physical degradation. Nickel and copper ions exhibited the lowest desorption rates. Due to their efficiency, CS can be a promising and low-cost alternative for removing metal ions. Adsorption ; Chemistry ; Desorption ; Sorption ; Metal ions in aqueous solution ; Cellulose ; Nickel ; Biosorption ; Ion exchange ; Copper ; Cadmium ; Inorganic chemistry ; Metal ; Nuclear chemistry ; Ion ; Organic chemistry Advanced Cellulose Research Studies ; Adsorption and biosorption for pollutant removal ; Electrokinetic Soil Remediation Techniques
Authors: Vincent Wagner
Source: Materials research proceedings (article, 2023-04-13)
Field: Materials Science — Materials Chemistry

Evolution of contact lengths during the turning of treated Ti64 β Abstract. One of the main ways to increase productivity during the machining of titanium alloy parts is to control the wear mechanisms and consequently the life of the cutting tools. The state-of-the-art shows wear phenomena generated mainly by diffusion. The latter is due to the intrinsic physical properties of titanium generating high temperatures on the cutting and relief faces. Concerning the secondary cutting zone, the wear phenomena result from thermomechanical actions induced by the contact between the secondary zone of the chip and the cutting face of the tool. The analysis of the contact lengths, divided into two parts (sliding contact and sticking contact), is then a strong indicator to be privileged in order to allow the understanding of the present mechanisms. This analysis is even more important when machining processed Ti64  in which chip formation is no longer periodic but a function of the angle between the primary shear band and the orientation of the individual colonies comprising the titanium. The purpose of this article is the analysis of the contact lengths during the machining of Ti64 treated  . After having presented the experimental device allowing visualising the evolution of the contact length between the chip and the cutting face, a statistical analysis based on the collected images makes it possible to put forward the differences of sliding behaviour on the cutting face. It appears that the distribution of the collected values allows explaining and extrapolating the wear appearing on the cutting face. Machining ; Materials science ; Titanium alloy ; Face (sociological concept) ; Titanium ; Chip formation ; Chip ; Diffusion ; Contact zone ; Tool wear ; Shear (geology) ; Mechanical engineering ; Computer science ; Composite material ; Metallurgy ; Alloy ; Geology ; Engineering ; Physics Titanium Alloys Microstructure and Properties ; Advanced machining processes and optimization ; Metal Alloys Wear and Properties
Authors: Kun Zhang | Ahmad El-Kharouf | Robert Steinberger‐Wilckens
Source: Research Square (preprint, 2023-02-14)
Field: Materials Science — Materials Chemistry

Effect of Temperature and Water Content on the Oxidation Behaviour and Cr Evaporation of High-Cr Steels for SOFC Cathode Air Preheaters Abstract Stainless steel is being investigated for use in cathode air pre-heater for solid oxide fuel cell systems because of its high thermal conductivity, formability, manufacturability, and superior mechanical properties. However, high temperature steels often contain a high concentration of Cr which presents a risk of evaporation and contaminating the cathode of the solid oxide fuel cell (SOFC). The oxidation and Cr 2 O 3 evaporation mechanisms of the stainless steels including Inconel 625, SS309, and AluChrom 318 have been investigated by varying temperatures and water content of the exposure atmosphere. For the influence of water content, samples of Inconel 625, SS309 and AluChrom 318 were isothermally exposed at 850°C in dry air and air containing 1%, 3% and 9% of H2O at a high flow rate for 168 hours. For the influence of temperature, samples of Inconel 625, SS309, and AluChrom 318 were isothermally exposed at 650°C, 750°C and 850°C in a 6.0 L/min air stream containing 3% H2O for 168 hours. The results of this study show that Cr 2 O 3 evaporation and oxidation rates were dramatically reduced with decreasing temperature for Inconel 625 and SS309. AluChrom 318 exhibited a decreased oxidation rate with decreasing temperature, but it demonstrated a reverse trend to the temperature dependent Cr 2 O 3 evaporation compared to Inconel 625 and SS309. The major effect of water vapour on the three tested materials appeared to be the further enhancement of Cr 2 O 3 evaporation. Inconel 625 ; Evaporation ; Materials science ; Cathode ; Metallurgy ; Isothermal process ; Inconel ; Oxide ; Chemical engineering ; Analytical Chemistry (journal) ; Chemistry ; Corrosion ; Environmental chemistry ; Thermodynamics Advancements in Solid Oxide Fuel Cells ; Electronic and Structural Properties of Oxides ; High-Temperature Coating Behaviors
Authors: Chutian Huang | Shuyang Dai | Xiaohua Niu | Tianpeng Jiang | Zhijian Yang | Yejun Gu | Yang Xiang
Source: arXiv (Cornell University) (preprint, 2023-04-12)
Field: Materials Science — Materials Chemistry

A Continuum Model for Dislocation Climb Dislocation climb plays an important role in understanding plastic deformation of metallic materials at high temperature. In this paper, we present a continuum formulation for dislocation climb velocity based on densities of dislocations. The obtained continuum formulation is an accurate approximation of the Green's function based discrete dislocation dynamics method (Gu et al. J. Mech. Phys. Solids 83:319-337, 2015). The continuum dislocation climb formulation has the advantage of accounting for both the long-range effect of vacancy bulk diffusion and that of the Peach-Koehler climb force, and the two longrange effects are canceled into a short-range effect (integral with fast-decaying kernel) and in some special cases, a completely local effect. This significantly simplifies the calculation in the Green's function based discrete dislocation dynamics method, in which a linear system has to be solved over the entire system for the long-range effect of vacancy diffusion and the long-range Peach-Koehler climb force has to be calculated. This obtained continuum dislocation climb velocity can be applied in any available continuum dislocation dynamics frameworks. We also present numerical validations for this continuum climb velocity and simulation examples for implementation in continuum dislocation dynamics frameworks. Climb ; Dislocation ; Vacancy defect ; Classical mechanics ; Dislocation creep ; Physics ; Statistical physics ; Mechanics ; Condensed matter physics ; Thermodynamics Microstructure and mechanical properties ; High Temperature Alloys and Creep ; Boron and Carbon Nanomaterials Research
Authors: Gobinda Garai | Bankim C. Mandal
Source: arXiv (Cornell University) (preprint, 2023-04-27)
Field: Materials Science — Materials Chemistry

Linear and Nonlinear Parareal Methods for the Cahn-Hilliard Equation In this paper, we propose, analyze and implement efficient time parallel methods for the Cahn-Hilliard (CH) equation. It is of great importance to develop efficient numerical methods for the CH equation, given the range of applicability of the CH equation has. The CH equation generally needs to be simulated for a very long time to get the solution of phase coarsening stage. Therefore it is desirable to accelerate the computation using parallel method in time. We present linear and nonlinear Parareal methods for the CH equation depending on the choice of fine approximation. We illustrate our results by numerical experiments. Cahn–Hilliard equation ; Computation ; Nonlinear system ; Range (aeronautics) ; Applied mathematics ; Computer science ; Mathematics ; Phase (matter) ; Mathematical analysis ; Algorithm ; Partial differential equation ; Physics ; Materials science Solidification and crystal growth phenomena
Authors: J. Zhang
Source: Materials research proceedings (article, 2023-02-26)
Field: Materials Science — Materials Chemistry

A coupled thermo-mechanical and neutron diffusion numerical model for irradiated concrete Abstract: Neutron irradiation plays an important role in nuclear-induced degradation for concrete shielding materials, specifically in determining the radiation induced volume expansion (RIVE) phenomenon driving its failure. When analyzing at the structural level the effects of nuclear radiation on concrete, a non-uniformed distribution of neutron radiation must be considered. This can be done via particle transport calculations preventive to the thermo-mechanic study, or by solving numerically the coupled set of governing equations of the problem. In this work the second approach is pursued in the theoretical framework of the Finite Element Method (FEM). The proposed formulation not only considers an accurate neutron transport model based on the two-group theory, but also it includes the effects induced by thermal neutrons to the temperature field. The formulation lends itself to include RIVE and the other relevant radiation induced effects on the mechanical field. The governing equations are presented and discussed, and some results obtained by using the general 3D numerical formulation proposed herein are compared to results from literature obtained via analytical methods addressing simplified 1D problems. Neutron ; Electromagnetic shielding ; Finite element method ; Neutron transport ; Work (physics) ; Radiation ; Diffusion ; Mechanics ; Physics ; Field (mathematics) ; Neutron radiation ; Materials science ; Nuclear physics ; Mathematics ; Thermodynamics Nuclear Materials and Properties ; Nuclear materials and radiation effects ; Nuclear reactor physics and engineering
Authors: Gao Kuang Hong | Lin Tie | Ma Xiao Rong | Li Qiu Lin | Qing Li
Source: arXiv (Cornell University) (preprint, 2023-08-20)
Field: Materials Science — Materials Chemistry

Disorder-induced linear magnetoresistance in Al$_2$O$_3$/SrTiO$_3$ heterostructures An unsaturated linear magnetoresistance (LMR) has attracted widely attention because of potential applications and fundamental interest. By controlling growth temperature, we realized a metal-to-insulator transition in Al2O3/SrTiO3 heterostructures. The LMR is observed in metallic samples with electron mobility varying over three orders of magnitude. The observed LMR cannot be explained by the guiding center diffusion model even in samples with very high mobility. The slope of the observed LMR is proportional to Hall mobility, and the crossover field, indicating a transition from quadratic (at low fields) to linear (at high fields) field dependence, is proportional to the inverse Hall mobility. This signifies that the classical model is valid to explain the observed LMR. More importantly, we develop an analytical expression according to the effective-medium theory that is equivalent to the classical model. And the analytical expression describes the LMR data very well, confirming the validity of the classical model. Heterojunction ; Magnetoresistance ; Condensed matter physics ; Crossover ; Inverse ; Quadratic equation ; Field (mathematics) ; Diffusion ; Magnetic field ; Physics ; Materials science ; Chemistry ; Mathematics ; Quantum mechanics ; Geometry ; Pure mathematics Electronic and Structural Properties of Oxides ; Magnetic and transport properties of perovskites and related materials ; Theoretical and Computational Physics