jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Alfred Kendem Djoumessi | Nicodème Rodrigue Sikame Tagne | Elvis Mbou Tiaya | François Gapgue | Ebernezer Njeugna
Source: Research Square (preprint, 2023-01-24)
Field: Materials Science — Polymers and Plastics

Thermo- physics behaviour of raphia vinifera/ Epoxy woven material: Experimental and theoretical approach Abstract This work deals with the analysis of the thermo-physical behavior of the raffia vinifiera/Epoxy bio-composite. The material is elaborated then, the thermal and physical properties are determined experimentally and theoretically. The experimental analysis of the thermal behavior is done by the hot plate method and that of the physical behavior it is done by the measuring the density and the kinetics of absorption which is used to evaluate the rate of absorption and the diffusion of water. The theoretical analysis, on the thermal conductivity used the model of Ning/Chou to homogenize the coefficient of conductivity and the method of finite elements in the software Abaqus C.A.E 6.14 to simulate the heat transfer through the composite; the theoretical determination of the density is done using the equation of Agrawal and Broutman. This work shows that the results obtained in experimental approach corroborate well with the theoretical ones. Moreover, this material presents very interesting characteristics such as a very low thermal conductivity which makes it a good insulating material on the one hand and on the other hand a low density (light and less absorbent material) compared to the wood species used in shipbuilding; thus, it is a suitable material for the construction of the superstructure of floating boats. Thermal conductivity ; Epoxy ; Materials science ; Work (physics) ; Composite material ; Diffusion ; Composite number ; Thermal diffusivity ; Heat transfer ; Material properties ; Conductivity ; Thermal ; Thermodynamics ; Physics Natural Fiber Reinforced Composites ; Textile materials and evaluations ; Material Properties and Processing
Authors: Toai Luong
Source: arXiv (Cornell University) (preprint, 2023-10-25)
Field: Materials Science — Materials Chemistry

Nonnegative Weak Solution to the Degenerate Viscous Cahn-Hilliard Equation The Cahn-Hilliard equation is a widely used model for describing phase separation processes in a binary mixture. In this paper, we investigate the viscous Cahn-Hilliard equation with a degenerate, phase-dependent mobility. We define the concept of a weak solution and establish the existence of such a solution by taking limits of solutions to the viscous Cahn-Hilliard equation with positive mobility. Additionally, assuming that the initial data is positive, we demonstrate that the weak solution remains nonnegative and is not identically zero. Finally, we prove that the weak solution satisfies an energy dissipation inequality. Cahn–Hilliard equation ; Degenerate energy levels ; Weak solution ; Dissipation ; Mathematics ; Physics ; Mathematical analysis ; Thermodynamics ; Partial differential equation Solidification and crystal growth phenomena ; Advanced Mathematical Modeling in Engineering ; Fluid Dynamics and Thin Films
Authors: Itsuki MORIMOTO | Kazushi KIMOTO | Katsuyuki Kawamura
Source: Japanese Journal of JSCE (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

ANALYSIS OF WATER MOLECULES AND CATIONS DISTRIBUTION IN MONTMORILLONITE INTERLAYER BY MOLECULAR DYNAMICS SIMULATIONS 高レベル放射性廃棄物の地層処分場における長期的な物質移行挙動を理解する上で，ベントナイト緩衝材の主成分であるモンモリロナイトの膨潤を定量的に予測する計算科学的手法を確立することは重要である．そのためには，マクロ膨潤の起源である粘土層間水と層間陽イオンの水和相互作用を分子スケールで十分に理解する必要がある．本研究では，モンモリロナイトの層間イオン種に応じた特徴的な膨潤を，水和構造の観点から調べることを目的として，Na 型及び Ca 型のモンモリロナイトの層間陽イオンと水分子の分布を分子動力学法により解析した．その結果， 陽イオンの水分子配位数が層間水量と陽イオン種によって異なること，それぞれの配位数とイオン種に特有の明確な水和構造を有することを明らかにした． Montmorillonite ; Molecular dynamics ; Molecule ; Chemical physics ; Distribution (mathematics) ; Dynamics (music) ; Chemistry ; Materials science ; Chemical engineering ; Computational chemistry ; Physics ; Mathematics ; Organic chemistry ; Mathematical analysis ; Engineering Radioactive element chemistry and processing ; Chemical Synthesis and Characterization ; Nuclear materials and radiation effects
Authors: Stefan Reinsch | T. Welter | Ralf Müller | Joachim Deubener
Source: Glass Europe (article, 2023-06-26)
Field: Materials Science — Ceramics and Composites

Hydrogen Permeability of Tectosilicate Glasses for Tank Barrier Liners The permeation of hydrogen gas was studied in meta-aluminous (tectosilicate) glass powders of Li2O×Al2O3×SiO2 (LAS), Na2O×Al2O3×SiO2 (NAS) and MgO×Al2O3×SiO2 (MAS) systems by pressure loading and vacuum extraction in the temperatures range 210–310 °C. With this method, both the solubility S and the diffusivity D were determined, while the permeability was given by the product SD. For all glasses, S was found to decrease with temperature, while D increased. Since the activation energy of diffusion of H2 molecules exceeded that of dissolution, permeation increased slightly with temperature. When extrapolated to standard conditions (25 °C), the permeability of tectosilicate glasses was found to be only 10-22–10-24 mol H2 (m s Pa)-1, which is 8–10 magnitudes lower than most polymers. Thin glass liners of these compositions are expected to be the most effective barrier for tanks of pressurised hydrogen. Permeation ; Thermal diffusivity ; Dissolution ; Permeability (electromagnetism) ; Solubility ; Hydrogen ; Materials science ; Atmospheric temperature range ; Activation energy ; Glass transition ; Diffusion ; Gaseous diffusion ; Polymer ; Analytical Chemistry (journal) ; Chemical engineering ; Mineralogy ; Composite material ; Thermodynamics ; Chemistry ; Chromatography ; Organic chemistry ; Fuel cells ; Membrane Glass properties and applications ; Advanced ceramic materials synthesis ; Thermal and Kinetic Analysis
Authors: Andreas Wagner | Pirmin Schlicke | Marvin Fritz | Christina Kuttler | J. Tinsley Oden | Christian Schumann | Barbara Wohlmuth
Source: arXiv (Cornell University) (preprint, 2023-03-16)
Field: Materials Science — Materials Chemistry

A phase-field model for non-small cell lung cancer under the effects of immunotherapy Formulating tumor models that predict growth under therapy is vital for improving patient-specific treatment plans. In this context, we present our recent work on simulating non-small-scale cell lung cancer (NSCLC) in a simple, deterministic setting for two different patients receiving an immunotherapeutic treatment. At its core, our model consists of a Cahn-Hilliard-based phase-field model describing the evolution of proliferative and necrotic tumor cells. These are coupled to a simplified nutrient model that drives the growth of the proliferative cells and their decay into necrotic cells. The applied immunotherapy decreases the proliferative cell concentration. Here, we model the immunotherapeutic agent concentration in the entire lung over time by an ordinary differential equation (ODE). Finally, reaction terms provide a coupling between all these equations. By assuming spherical, symmetric tumor growth and constant nutrient inflow, we simplify this full 3D cancer simulation model to a reduced 1D model. We can then resort to patient data gathered from computed tomography (CT) scans over several years to calibrate our model. For the reduced 1D model, we show that our model can qualitatively describe observations during immunotherapy by fitting our model parameters to existing patient data. Our model covers cases in which the immunotherapy is successful and limits the tumor size, as well as cases predicting a sudden relapse, leading to exponential tumor growth. Finally, we move from the reduced model back to the full 3D cancer simulation in the lung tissue. Thereby, we show the predictive benefits a more detailed patient-specific simulation including spatial information could yield in the future. Lung cancer ; Ode ; Context (archaeology) ; Immunotherapy ; Cancer ; Computer science ; Cancer immunotherapy ; Medicine ; Applied mathematics ; Oncology ; Mathematics ; Internal medicine ; Biology Solidification and crystal growth phenomena ; Mathematical Biology Tumor Growth ; Advanced Mathematical Modeling in Engineering
Authors: Russell A. Brown
Source: arXiv (Cornell University) (preprint, 2023-07-31)
Field: Chemistry — Spectroscopy

Pulse Sequences to Observe NMR Coupled Relaxation in AXn Spin Systems NMR pulse sequences that are modifications of the HSQC experiment are proposed to observe ${}^{13}\textrm{C}$-coupled relaxation in AX, AX$_2$, and AX$_3$ spin systems. ${}^{13}\textrm{CH}$ and ${}^{13}{\textrm{CH}}_2$ moieties are discussed as exemplary AX and AX$_2$ spin systems. The pulse sequences may be used to produce 1D or 2D proton NMR spectra. Pulse (music) ; Spin (aerodynamics) ; Relaxation (psychology) ; Heteronuclear single quantum coherence spectroscopy ; Pulse sequence ; Physics ; Proton ; Spectral line ; Proton NMR ; Nuclear magnetic resonance ; Two-dimensional nuclear magnetic resonance spectroscopy ; Chemistry ; Condensed matter physics ; Quantum mechanics ; Thermodynamics Advanced NMR Techniques and Applications ; NMR spectroscopy and applications ; Molecular spectroscopy and chirality
Authors: Yanbao Ma | Zhengxian Qu | Juhao Wu
Source: Research Square (preprint, 2023-08-22)
Field: Materials Science — Materials Chemistry

Heat Propagation: A Fourth Mechanism Allowing Heat Transfer from Cold to Hot Abstract Fourier's law, governing heat conduction through temperature gradients, has been invalidated by heat waves observed in cryogenic heat-pulse experiments and reduced effective thermal conductivity (ETC) in nanoscale heat transfer. Despite persistent efforts over 150 years to find a replacement, this intriguing problem remains unresolved. Moreover, the root cause of reduced ETC and the generation mechanism and speed of second sound in hydrodynamic heat transfer have remained elusive. Our investigation reveals a groundbreaking discovery: a temperature-gradient-independent propagation of heat, encompassing both ballistic and hydrodynamic transfer, enables heat transfer from cold to hot without violating the Second Law of Thermodynamics. This identifies heat propagation as a fourth mechanism alongside conduction, convection, and radiation, revolutionizing traditional understanding of heat transfer beyond hot-to-cold scenarios. This discovery exposes the root cause for the breakdown of Fourier’s law and leads to a physics-based propagation-diffusion model to replace Fourier’s law. Incorporating the collective particle-wave duality of phonons, this model successfully replicates heat-pulse experiments and attributes reduced ETC to delayed heating effects. Furthermore, it challenges the established theory of hydrodynamic heat transfer driven by temperature gradients, offering an exceptionally efficient approach to thermal management, surpassing thermal conductivity limits, with profound implications across scientific and engineering disciplines. Mechanism (biology) ; Heat transfer ; Mechanics ; Physics Thermal properties of materials ; Thermal Radiation and Cooling Technologies ; Heat Transfer and Optimization
Authors: Morteza Nadi | Seyed Hassan Sedighy | A. Cheldavi
Source: Research Square (preprint, 2023-06-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Multimode OAM beam generation through 1-Bit programmable metasurface antenna for high throughput data communications Abstract In modern wireless communication, the orbital angular momentum (OAM) beam is considered as an important technology. Some considerable efforts have been devoted to using this technology for channel capacity enhancement as much as possible. Nowadays, programmable metasurfaces provide an innovational scenario for generating multi-mode OAM beams due to their ability for digital electromagnetic waves modulation. However, the current programmable metasurfaces for generating OAM beams are typically based on reflective and transmissive modes, which have low aperture efficiency due to spillover and illumination effects. In this paper, a 1-bit programmable metasurface antenna is proposed with capability of producing highly efficient dynamic multi-mode OAM beams. The proposed structure is consisted of electronically reconfigurable meta-radiating elements loaded by PIN diodes to generate two-phase states of electric field. The designed Field Programmable Gate Array (FPGA) can assign a code sequence of 0 or 1 to the metasurface antenna in real-time to generate multi-mode OAM beams. Hence, a dynamical surface is obtained by switching PIN diodes to change the phase distribution on the surface. To verify the concept, the metasurface antenna is fabricated and measured with different OAM beam states, which are in agreement with the full-wave simulations, properly. The designed structure introduces a capable multi-mode OAM alternative for high throughput mm-wave communications. PIN diode ; Antenna (radio) ; Beam (structure) ; Field-programmable gate array ; Throughput ; Optics ; Computer science ; Reconfigurable antenna ; Electronic engineering ; Diode ; Wireless ; Physics ; Engineering ; Electrical engineering ; Omnidirectional antenna ; Telecommunications ; Computer hardware ; Antenna efficiency Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Antenna Design and Analysis
Authors: T. Hageman | E. Martínez-Pañeda
Source: arXiv (Cornell University) (preprint, 2023-07-03)
Field: Materials Science — Materials Chemistry

A phase field-based framework for electro-chemo-mechanical fracture: crack-contained electrolytes, chemical reactions and stabilisation We present a new theoretical and computational framework for modelling electro-chemo-mechanical fracture. The model combines a phase field description of fracture with a fully coupled characterisation of electrolyte behaviour, surface chemical reactions and stress-assisted diffusion. Importantly, a new physics-based formulation is presented to describe electrolyte-containing phase field cracks, appropriately capturing the sensitivity of electrochemical transport and reaction kinetics to the crack opening height. Unlike other existing methods, this approach is shown to accurately capture the results obtained with discrete fracture simulations. The potential of the electro-chemo-mechanical model presented is demonstrated by particularising it to the analysis of hydrogen embrittlement in metallic samples exposed to aqueous electrolytes. The finite element implementation takes as nodal degrees-of-freedom the electrolyte potential, the concentrations of relevant ionic species, the surface coverage, the concentration of diluted species, the displacement field and the phase field order parameter. Particular attention is devoted to improve stability and efficiency, resulting in the development of strategies for avoiding ill-constrained degrees of freedom and lumped integration schemes that eliminate numerical oscillations. The numerical experiments conducted showcase the ability of the model to deliver assumptions-free predictions for systems involving both free-flowing and crack-contained electrolytes. The results obtained highlight the role of electrolyte behaviour in driving the cracking process, evidencing the limitations of existing models. Electrolyte ; Fracture (geology) ; Materials science ; Field (mathematics) ; Phase (matter) ; Mechanics ; Hydrogen embrittlement ; Finite element method ; Electrochemistry ; Displacement (psychology) ; Degrees of freedom (physics and chemistry) ; Composite material ; Thermodynamics ; Chemistry ; Physics ; Electrode ; Corrosion ; Mathematics ; Physical chemistry Corrosion Behavior and Inhibition ; Numerical methods in engineering ; Non-Destructive Testing Techniques
Authors: Tingting Wu | Yaqi Zhang | Lijie Ma | Bolin Wu
Source: International Journal of Applied Ceramic Technology (article, 2023-06-18)
Field: Materials Science — Ceramics and Composites

Processing of alumina grinding media using scandia as a sintering aid Abstract Wear resistance is one of the essential properties of grinding media. Good wear resistance is the quality guarantee of preparing high‐purity ultrafine powder. This paper mainly studied the influence rule and enhanced mechanism of Sc 2 O 3 on the wear resistance of Al 2 O 3 ceramics. The relationship between Sc 2 O 3 content and sintering properties, wear resistance, and microstructure of ceramics was studied. According to research findings, Sc 2 O 3 could promote the densification of ceramics, improve the morphology of grain boundaries, enhance the binding force of grains, and increase the mechanical property of alumina grain. Materials science ; Sintering ; Grinding ; Microstructure ; Ceramic ; Wear resistance ; Metallurgy ; Grain size ; Grain boundary ; Alumina ceramic Advanced ceramic materials synthesis ; Advanced materials and composites ; Injection Molding Process and Properties
Authors: Yue Li | Lei Wang | Junjie Li | Jincheng Wang | Zhijun Wang
Source: arXiv (Cornell University) (preprint, 2023-03-31)
Field: Materials Science — Materials Chemistry

Phase Field Model for Non-equilibrium Interface Conditions This article presents a new phase-field formulation for non-equilibrium interface conditions in rapid phase transformations. With a particular way of defining concentration fields, the classical sharp and diffuse (thick) interface theories are unified into the present phase-field model. Each point inside the diffuse interface is comparable to the classical sharp interface model, governed by phase boundary migration and short-range atomic exchanges and connected by long-range diffusion. Their thermodynamic forces and fluxes are following the Onsager reciprocal relation and consistent with the classical irreversible thermodynamics. Furthermore, we establish the balance of driving forces and energy dissipations for both the diffuse interface and the single point inside it. The model is then validated by rapid solidification of Al-Cu alloys. With an effective mobility of considering non-equilibrium long-range diffusion, the model represents the main characteristics of non-equilibrium interface kinetics, i.e., solute trapping and solute drag. Especially, we reproduce the complete trapping at the high-velocity regime and provide a thermodynamic consistent description of the partial drag phenomena at the low-velocity region. Moreover, the dissipation analysis indicates that even the far-from-equilibrium diffuse interface is composed of numerous representative volume elements near the equilibrium, providing a new understanding of non-equilibrium interfaces. Diffusion ; Dissipation ; Thermodynamic equilibrium ; Drag ; Phase (matter) ; Solvent drag ; Range (aeronautics) ; Thermodynamics ; Field (mathematics) ; Phase field models ; Equilibrium thermodynamics ; Phase boundary ; Mechanics ; Statistical physics ; Physics ; Materials science ; Grain boundary Solidification and crystal growth phenomena ; nanoparticles nucleation surface interactions ; Aluminum Alloy Microstructure Properties
Authors: Lingyun Ding
Source: arXiv (Cornell University) (preprint, 2023-03-25)
Field: Chemistry — Physical and Theoretical Chemistry

Shear dispersion of multispecies electrolyte solutions in the channel domain In multispecies electrolyte solutions, even in the absence of an external electric field, differences in ion diffusivities induce an electric potential and generate additional fluxes for each species. This electro-diffusion process is well-described by the advection-Nernst-Planck equation. This study aims to analyze the long-time behavior of the governing equation under electroneutrality and zero current conditions and investigate how the diffusion-induced electric potential and shear flow enhance the effective diffusion coefficients of each species in channel domains. The some exact solutions of the effective equation and the asymptotic analyses for ions with large diffusivity discrepancies are presented. Furthermore, there are several interesting properties of the effective equation. First, it is a generalization of the Taylor dispersion, with a nonlinear diffusion tensor replacing the scalar diffusion coefficient. Second, the effective equation exhibits a scaling relation, revealing that the system with a weak flow is equivalent to the system with a strong flow under scaled physical parameters. Third, in the case of injecting a lower-concentration electrolyte solution into a pre-existing solution with the same ion species, the effective equation simplifies to a multidimensional diffusion equation. However, when introducing the electrolyte solution into a channel filled with deionized water, the ion-electric interaction results in several phenomena do not present in the advection-diffusion equation, including upstream migration of some species, spontaneous separation of ions, and non-monotonic dependence of the effective diffusivity on Péclet numbers. Last, the dependence of effective diffusivity on concentration and ion diffusivity suggests a method to infer the concentration ratio of each component and ion diffusivity by measuring the effective diffusivity. Thermal diffusivity ; Electrolyte ; Diffusion equation ; Taylor dispersion ; Electric field ; Ion ; Chemistry ; Thermodynamics ; Diffusion ; Mechanics ; Materials science ; Physics Electrostatics and Colloid Interactions ; Membrane-based Ion Separation Techniques
Authors: В. В. Семенов | Xavier Porté | Laurent Larger | Daniel Brunner
Source: arXiv (Cornell University) (preprint, 2023-02-27)
Field: Materials Science — Materials Chemistry

Deterministic and stochastic coarsening control in optically-addressed spatial light modulators subject to optical feedback Phase separation accompanied by further domain growth and coarsening is a phenomenon common to a broad variety of dynamical systems. In this connection, controlling such processes represents a relevant interdisciplinary problem. Using methods of numerical modelling, we demonstrate two approaches for the coarsening control in bistable systems based on the example of a spatially-extended model describing an optically-addressed spatial light modulator with two color illumination subject to optical feedback. The first method implies varying system parameters such that the system evolves as the pitchfork or saddle-node normal forms. The second method leverages noise whose intensity is used as an additional system parameter. Both, deterministic and stochastic schemes allow to control the direction and speed of the fronts separating spatial domains. The considered stochastic control represents a particular case of the noise-sustained front propagation in bistable systems and involves the properties of the optical system under study. In contrast, the proposed deterministic control technique can be applied to bistable systems of different nature. Bistability ; Noise (video) ; Computer science ; Control theory (sociology) ; Optical bistability ; Node (physics) ; Optics ; Control (management) ; Physics ; Nonlinear optics ; Optoelectronics ; Artificial intelligence ; Laser Solidification and crystal growth phenomena ; Theoretical and Computational Physics ; nanoparticles nucleation surface interactions