jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yi-Fan Hou | Quanhao Zhang | Pavlo O. Dral
Source: ChemRxiv (preprint, 2024-06-19)
Field: Chemistry — Organic Chemistry

Surprising new dynamics phenomena in Diels–Alder reaction of C60 uncovered with AI Our recently developed physics-informed active learning allowed us to perform extensive AI-accelerated quasi-classical molecular dynamics investigation of the time-resolved mechanism of Diels–Alder reaction of fullerene C60 with 2,3-dimethyl-1,3-butadiene. In a substantial fraction (10%) of reactive trajectories, the larger C60 non-covalently attracts the 2,3-dimethyl-1,3-butadiene long before the barrier so that the diene undergoes the series of complex motions including roaming, somersaults, twisting, and twisting somersaults around the fullerene until it aligns itself to pass over the barrier. These complicated processes could be easily missed in typically performed quantum chemical simulations with shorter and fewer trajectories. After passing the barrier, the bonds take longer to form compared to the simplest prototypical Diels–Alder reaction of ethene with 1,3-butadiene despite high similarities in transition states and barrier widths evaluated with intrinsic reaction coordinate (IRC) calculations. Alder ; Diels–Alder reaction ; Dynamics (music) ; Chemistry ; Sociology ; Ecology ; Biology ; Organic chemistry Fullerene Chemistry and Applications ; Advanced Physical and Chemical Molecular Interactions ; Advanced Thermodynamics and Statistical Mechanics
Authors: Geraldine Anis | Thomas Hudson | P.E. Brommer
Source: Physical Review Materials (article, 2024-12-16)
Field: Materials Science — Materials Chemistry

Dislocation dynamics in Ni: Parameterizing dislocation trajectories from atomistic simulations We present a methodology using Differential Evolution Monte Carlo (DE-MC) to fit the parameters of an equation of motion to molecular dynamics (MD) trajectories of an <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mfrac><a:mi>a</a:mi><a:mn>2</a:mn></a:mfrac><a:mrow><a:mo>〈</a:mo><a:mn>110</a:mn><a:mo>〉</a:mo></a:mrow><a:mrow><a:mo>{</a:mo><a:mn>111</a:mn><a:mo>}</a:mo></a:mrow></a:mrow></a:math> edge dislocation in pure face-centered cubic (FCC) Ni, which is used as a model system. The motion of the edge dislocation under shear was observed using MD simulations with a classical effective potential, and the dislocation position was extracted. The parameters of interest were the effective mass, drag coefficient, and force experienced by the dislocation. Using DE-MC within a Bayesian framework, we estimated the joint posterior distribution of the parameters from the accepted samples produced by the DE-MC algorithm. The obtained distribution was then used to propagate the parameter uncertainties through the model, the equation of motion, which was used to predict the dislocation positions and velocities at the simulation timesteps as well as the uncertainty in the predictions. The mean fit was found to match the MD dislocation position data with a root mean square error (RMSE) of <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mn>0.2</b:mn><b:mspace width="0.16em"/><b:mi mathvariant="normal">n</b:mi><b:mi mathvariant="normal">m</b:mi></b:mrow></b:math>. We demonstrate how parameter distributions determined using the proposed methodology can be applied to obtain a mobility law for the class of dislocations studied with quantified uncertainties. This work is part of a longer-term study aiming to develop a surrogate model for precipitation strengthening, specifically dislocation-precipitate interactions, in Ni-based superalloys with uncertainty quantification. Accordingly, we also discuss the limitations of the selected model within this context and the necessary model extensions to overcome them. Published by the American Physical Society 2024 Dislocation ; Materials science ; Molecular dynamics ; Position (finance) ; Monte Carlo method ; Crystallography ; Statistical physics ; Physics ; Mathematics ; Chemistry ; Statistics ; Quantum mechanics Microstructure and mechanical properties ; High Temperature Alloys and Creep ; Aluminum Alloy Microstructure Properties
Authors: M. Ramish Ashraf | Stavros Melemenidis | Joseph B. Schulz | Billy W. Loo
Source: International Journal of Radiation Oncology*Biology*Physics (article, 2024-09-27)
Field: Materials Science — Surfaces, Coatings and Films

Monte Carlo Based Treatment Planning Workflow for Pre-Clinical and Clinical Electron Flash Studies Workflow ; Monte Carlo method ; Flash (photography) ; Computer science ; Physics ; Statistics ; Mathematics ; Database Electron and X-Ray Spectroscopy Techniques ; Machine Learning in Materials Science ; Semiconductor materials and devices
Authors: Tariq Khraishi | Georges Ayoub | Sinisa Dj. Mesarovic | Mutasem A. Shehadeh
Source: Journal of Materials Science (article, 2024-03-01)
Field: Materials Science — Materials Chemistry

Preface: the physics of metal plasticity Solid mechanics ; Materials science ; Plasticity ; Polymer science ; Engineering physics ; Engineering ethics ; Nanotechnology ; Physics ; Composite material ; Engineering Microstructure and mechanical properties ; Microstructure and Mechanical Properties of Steels ; Force Microscopy Techniques and Applications
Authors: Sara Valdez | Carmen B. Dunn | Miya D. Hullum | Evains Harper | Zhe Qiang
Source: Journal of Chemical Education (article, 2024-06-05)
Field: Chemistry — Physical and Theoretical Chemistry

Reprocessable Networks from Vegetable Oils, Salts, and Food Acids: A Green Polymer Outreach Demonstration for Middle School Students Massive amounts of mismanaged plastic waste have led to growing concerns about their adverse impacts on the environment, ecosystem, and human health. Enabling efficient plastic recycling is a key component for developing a sustainable future, which requires cohesive efforts in technology innovations, public awareness, and workforce development. Particularly, outreach activities to inform the broader community about current efforts to fabricate sustainable polymeric materials can play a central role in inspiring future generations while also improving their knowledge, viewpoints, and behaviors to address plastic waste challenges. Herein, this account demonstrates an effort to educate middle school students about a key emerging concept in polymer science for sustainable material development: reprocessable polymer networks. Background information is provided to the students about the need to transition from petroleum-based chemical feedstocks to their bioderived counterparts. We note that the materials used in this demonstration lesson are all produced from common household foods, with which students routinely interact in various applications, making them not only safe but also compelling for the middle school classroom. Outreach ; Viewpoints ; Workforce ; Sustainable development ; Business ; Political science Various Chemistry Research Topics ; Chemistry and Chemical Engineering ; Microplastics and Plastic Pollution
Authors: Q.H. Jebur | Mohsin Noori Hamzah | Muhsin J. Jweeg | Emad Kadum Njim | Muhannad Al‐Waily | Kadhim K. Resan
Source: Jurnal Teknologi (article, 2024-08-12)
Field: Materials Science — Polymers and Plastics

MODELING HYPERPLASTIC ELASTOMER MATERIALS USED IN TIRE COMPOUNDS: NUMERICAL AND EXPERIMENTAL STUDY Analyzing the rubber components of a tire, including the tread and sidewall, is crucial for assessing tire performance attributes. This evaluation enhances vehicle dynamics control and safety levels. Both finite element analysis and experimental tests are employed in this study to achieve accurate estimations. This study centers on Iraqi-manufactured tread and sidewall tires while delving into specific Dunlop components like tread and sidewalls. A highly effective methodology has been developed to ascertain material properties through experimental analysis of hyperelastic rubber models in tires. This approach is executed using ABAQUS, a widely employed commercial finite element software. Addressing rubber's intricate and diverse interactions through a straightforward yet precise phenomenological model holds immense industrial significance. Creating universally applicable design principles for these components remains a persistent challenge in modern industry. This study utilizes simulations to analyze stress-strain responses and compute material parameters for hyperelastic rubber models under tensile loading, employing computer-aided engineering (CAE) to represent stress-strain behavior, especially with varying strain amplitudes comprehensively. Focusing on elastomers, the study assesses the Ogden, Mooney-Rivlin, and reduced polynomial models by extracting coefficients from laboratory tests. It combines experimental and numerical methods to establish validated material constants. Most models yield reasonable results with acceptable deviations. The Neo-Hookean model is the simplest, fitting data up to 30% strain. The moderately complex Mooney-Rivlin and reduced polynomial models accommodate strains up to 100%. While accurate, the Ogden model exhibits higher nonlinearity and increased computational demands based on the material parameters. Elastomer ; Materials science ; Composite material ; Structural engineering ; Engineering Polymer Nanocomposites and Properties
Authors: Kenji Murata | Ta‐Te Chen | Fei Sun | Yoshitaka Adachi
Source: Modelling and Simulation in Materials Science and Engineering (article, 2024-09-17)
Field: Materials Science — Materials Chemistry

Cellular automaton simulation of solid-phase grain growth under conditions involving scanning heat sources and temperature gradients Abstract A cellular automaton simulation of grain growth in a solid phase was conducted, considering the temperature gradient, heat source movement, and conditions favoring prioritized grain growth. The results reveal that, under optimal conditions, cellular grains elongated in the direction of the heat source movement. Detailed simulations illustrate the dynamics of grain growth and effect of mobility and driving forces on the dynamics, providing valuable insights into cellular grain growth in a solid phase. Cellular automaton ; Materials science ; Grain growth ; Phase (matter) ; Dynamics (music) ; Grain size ; Temperature gradient ; Mechanics ; Biological system ; Chemical physics ; Composite material ; Computer science ; Physics ; Meteorology ; Biology Solidification and crystal growth phenomena
Authors: Diego Lauer | J. W. González | Eric Suárez Morell | A. Ayuela
Source: arXiv (Cornell University) (preprint, 2024-11-28)
Field: Materials Science — Materials Chemistry

Optimizing Hubbard U parameters for Enhanced Description of Electronic and Magnetic Properties in CrI$_3$ Monolayers and Bilayers The magnetic properties of CrI$_3$ monolayers, which were recently measured, have been investigated considering electronic repulsion and localization effects in Cr 3d orbitals. In this study, we propose a DFT approach using Hubbard U corrections to improve accuracy. We compare the valence density-of-states using the HSE06 hybrid functional and the DFT+U approach, which includes U parameters for both Cr 3d and I 5p orbitals. The results of our study indicate that the optimal values for U(Cr$_{3d}$) and U(I$_{5p}$) are 3.5 eV and 2.0 eV, respectively. This approach is further applied to improve calculations of electronic and magnetic properties in CrI$_3$ monolayers and, more importantly, in bilayers combined with van der Waals functionals. These refinements hold promise for further studies of complex CrI$_3$ nanostructures, and may also be of interest for other trihalide few-layer systems. Magnetism ; Monolayer ; Materials science ; Condensed matter physics ; Nanotechnology ; Physics Machine Learning in Materials Science ; 2D Materials and Applications ; Inorganic Chemistry and Materials
Authors: Lidyawati Lidyawati
Source: JURNAL SERAMBI ILMU (article, 2024-02-06)
Field: Chemistry — Physical and Theoretical Chemistry

Determination of Preservative Levels of Sodium Benzoate in Packaged Mayonnaise UV-Vis Spectrophotometry as an Effort to Improve Practice Experience Basic Chemistry Course Students Sodium benzoate is the sodium salt of benzoic acid which is often used in processed foods and beverages, According to the regulation of the Head of BPOM RI No. 36 of 2013, this preservative is permitted in its use but has a limit on the use of mayonnaise, which is 1000 mg/kg body weight. The purpose of this study was to determine the content of sodium benzoate and the levels in packaged mayonnaise. This research was conducted at the Chemistry Laboratory of the Faculty of Teacher Training and Education, Syiah Kuala University, Banda Aceh to improve the student learning experience in basic chemistry courses, using five samples of packaged mayonnaise. The results showed that the five samples of packaged mayonnaise were positive for the preservative sodium benzoate. Determination of the preservative content of Sodium benzoate was determined using UV-Vis spectrophotometry method at max 280 nm. From the measurement results, the sodium benzoate content of sample M1 = 68 mg/kg, sample M2 = 35.5 mg/kg, sample M3 = 85.5 mg/kg, sample M4 = 95.5 mg/kg and M5 mg/kg = 30.5 and the use of preservative sodium benzoate in the packaged mayonnaise does not exceed the maximum limit that has been set. Preservative ; Sodium benzoate ; Chemistry ; Food science ; Spectrophotometry ; Chromatography Various Chemistry Research Topics
Authors: P. Alex Greaney | S. Aria Hosseini | Laura de Sousa Oliveira | Alathea E. Davies | Neophytos Neophytou
Source: Nanomaterials (article, 2024-05-03)
Field: Materials Science — Materials Chemistry

Super-Suppression of Long-Wavelength Phonons in Constricted Nanoporous Geometries In a typical semiconductor material, the majority of the heat is carried by long-wavelength, long-mean-free-path phonons. Nanostructuring strategies to reduce thermal conductivity, a promising direction in the field of thermoelectrics, place scattering centers of size and spatial separation comparable to the mean free paths of the dominant phonons to selectively scatter them. The resultant thermal conductivity is in most cases well predicted using Matthiessen's rule. In general, however, long-wavelength phonons are not as effectively scattered as the rest of the phonon spectrum. In this work, using large-scale molecular-dynamics simulations, non-equilibrium Green's function simulations, and Monte Carlo simulations, we show that specific nanoporous geometries that create narrow constrictions in the passage of phonons lead to anticorrelated heat currents in the phonon spectrum. This effect results in super-suppression of long-wavelength phonons due to heat trapping and reductions in the thermal conductivity to values well below those predicted by Matthiessen's rule. Nanoporous ; Phonon ; Wavelength ; Materials science ; Condensed matter physics ; Optics ; Optoelectronics ; Physics ; Nanotechnology Thermal properties of materials ; Thermal Radiation and Cooling Technologies ; Ultrasonics and Acoustic Wave Propagation
Authors: Katheryn Ure | Irene Bal
Source: Journal of Technology-Integrated Lessons and Teaching (article, 2024-01-20)
Field: Chemistry — Physical and Theoretical Chemistry

Synthesizing Magnesium Oxide through a 3D Experience This lesson is from the Types of Reactions unit in a High School Chemistry class and focuses on the synthesis of magnesium oxide. The purpose of this lesson is for students to conduct a lab experiment, and understand, at an atomic level, how the reaction occurs. In collaboration between a Chemistry teacher and Educational Technology faculty member, one three-dimensional (3D) experience was created to support the visualization of the reaction and minimize the students’ misconceptions. Magnesium ; Mathematics education ; Class (philosophy) ; Visualization ; Chemistry ; Oxide ; Computer science ; Psychology ; Organic chemistry ; Artificial intelligence Various Chemistry Research Topics ; Innovative Teaching and Learning Methods
Authors: Lars UHLMANN
Source: Materials research proceedings (article, 2024-04-19)
Field: Materials Science — Materials Chemistry

Influence of surface treatments on the fatigue strength of cross bores in shafts from EN-GJS700-2 Abstract. The European Union's Federal Climate Protection Act mandates a 55 % reduction in greenhouse gas emissions from 1990 levels by 2030, aiming for climate neutrality by 2050. Achieving these goals requires emission cuts across sectors, including energy, industry, and transportation. Lightweight design in transportation, achieved through alternative materials, geometry optimization, or enhanced fatigue strength, is vital. Highly stressed components like shafts are prone to failure due to notch locations which reduces the fatigue strength significantly. Inducing compressive residual stresses through methods like deep rolling and shot peening may improve the fatigue strength by reducing critical tensile load stresses. This study compares the fatigue strength of shaft cross bores treated with induction hardening, deep rolling, shot peening, and the combination of induction hardening and deep rolling. The research aims to establish a cause-effect relationship between surface layer properties and fatigue strength, considering the redistribution of residual stresses during testing. Materials science Metal Alloys Wear and Properties ; Surface Treatment and Coatings ; Mechanical and Thermal Properties Analysis
Authors: Nur Farha Shaafi | Mohammad Mubarrak Mohd Yusof | Ellianawati Ellianawati | Bambang Subali | Muhammad Haziq Hazim Raji’e
Source: Journal of Education and Learning (EduLearn) (article, 2024-07-13)
Field: Chemistry — Physical and Theoretical Chemistry

Investigating misconceptions about acids and bases among pre-service science teachers This study examines prevalent misconceptions among students regarding the fundamental concepts of acids and bases, which often arise during the learning process. This study aims to pinpoint misconceptions held by pre-service science teachers in the realm of acids and bases; 117 university students from diverse educational backgrounds, enrolled in three distinct courses: Biology, Chemistry, and Physics from the Faculty of Education, participated in the study. Using a structured questionnaire, the research identified 11 misconceptions out of 26 items related to acid and base concepts among pre-service teachers, while 15 items showed a correct understanding. Notably, three misconceptions exhibit the highest prevalence, namely the universal indicator of strong alkali (71.7%), the calculation-related concentration of acids and bases (69.3%), and the procedural steps for preparing a solution with a specified concentration using the dilution method (65.8%). The analysis indicates that although pre-service teachers generally understand acid and base concepts well, some misconceptions persist. Additionally, correlations between gender, university major, and understanding of these concepts were found. Further global research is recommended to identify misconceptions among university students. Comprehensive research in Malaysia could help educators and students address these misconceptions in Chemistry education. Mathematics education ; Science education ; Service (business) ; Psychology ; Medical education ; Medicine ; Business Various Chemistry Research Topics ; Science Education and Pedagogy
Authors: Toshinori Matsumoto | Takashi Hibiki | Yu Maruyama
Source: International Journal of Energy Research (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Analysis of Ex‐Vessel Debris Coolability of Boiling Water Reactors To evaluate the effectiveness of the wet cavity strategy, the authors developed a stochastic evaluation method that considers the uncertainties of the molten material conditions ejected from reactor pressure vessels. This study analyzed the probability of ex‐vessel debris coolability under the wet cavity strategy. The first step was uncertainty analysis using the severe accident analysis code MELCOR to obtain the melt condition. Five uncertainty parameters related to the core degradation and transfer process were chosen. With the assumed probabilistic distributions, the input parameter sets were generated using the Latin hypercube sampling (LHS) method. Analyses were conducted, and the conditions of the melt were obtained. The second step was to analyze the melt behavior in the water and the spreading radius using the JASMINE code and to calculate the height of the debris on the floor. The probabilistic distribution of parameters for the JASMINE analyses was determined from the MELCOR analysis results. LHS generated 200 parameter sets. The depths of the water pool in the analysis were 0.5, 1.0, and 2.0 m. The debris height was compared with the criterion to judge its coolability. Consequently, the probability of successful debris cooling was obtained through the sequence of calculations. The feasibility and technical difficulties in the MELCOR‐JASMINE combined analysis were also discussed. Boiling ; Nuclear engineering ; Boiling water reactor ; Natural circulation ; Debris ; Environmental science ; Waste management ; Engineering ; Thermodynamics ; Meteorology ; Physics Nuclear Materials and Properties ; Nuclear Engineering Thermal-Hydraulics ; Nuclear reactor physics and engineering
Authors: Universidad de Antioquia | Angélica Turizo-Donado | Samuel López-Zapata | Silvana Arias | John R. Agudelo
Source: Revista Facultad de Ingeniería Universidad de Antioquia (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Methodologies for alternative jet fuels testing on small-scale reaction engines The aviation industry increasingly recognizes that achieving climate neutrality is evolving into a fundamental and enduring asset for long-term competitiveness. In light of this, this paper provides a comprehensive review of the methodologies used to test alternative jet fuels (AJF) for aviation, which are renewable energy sources with the potential to replace conventional petroleum-derived fuels. It presents the types of AJF tested, focusing on the distinction between drop-in fuels and others. The article encapsulates the results from these tests, particularly concerning the performance and emissions aspects of the biojets, and their impact on engine materials and components. It outlines the equipment and techniques utilized in these tests, highlighting the advantages of using assemblies with miniature engines or combustors for a faster, easier, and more cost-effective preliminary assessment of biojet fuels. The paper also addresses future research directions, such as investigating the long-term impacts on engine lifespan and maintenance, and the potential to increase the blending ratio with conventional fuel. Lastly, it provides an overview of the situation in Colombia, where palm oil biodiesel has been tested, and points out the need for further research on other types of biojets for aviation. Jet fuel ; Scale (ratio) ; Environmental science ; Jet engine ; Process engineering ; Computer science ; Nuclear engineering ; Aerospace engineering ; Engineering ; Physics Catalytic Processes in Materials Science ; Nuclear reactor physics and engineering ; Heat transfer and supercritical fluids