jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Maria Berdik | Maria Blaginina | Zefanja Beckles | Radmir Laipanov
Source: Material and Mechanical Engineering Technology (article, 2024-10-01)
Field: Materials Science — Materials Chemistry

Research of the Causes of Defects Type “Dent” on the Linear Part of the Main Pipelines This article discusses the main reasons for the formation of defects such as dents on the main pipelines. As a rule, the presence of dents is typical for laying in conditions of rocky soil or permafrost. In this case, fairly large rock fragments appear at the base of the trench, which act on the pipe with a force equal to the weight of the pipe and the weight of the back fill soil. This is why most of the dents form on the bottom surface of the pipe. As a method of combating the formation of dents, back filling of soft soil at the base of the trench is usually used, but these measures lose their effectiveness because over time the soil from the base of the trench is washed away and the metal of the pipe comes into contact with the stone fragment. This article examines the process of dent formation through numerical simulation. The procedure for modeling is considered, and the results obtained are analyzed. The dimensions and shape of the dents obtained during numerical modeling coincide with the parameters of the dents recorded on real objects. The purpose is to study the mechanism of death formation on large diameter pipes under the influence of static load caused by external force factors. The scientific novelty lies in the refutation of the theory suggesting the possibility of dents on large diameter steel pipelines solely as a result of dynamic action from moving parts of the construction equipment or pipe impact during a fall. The study proved that a dent can form under the influence of static load. The parameters of the dent obtained during the simulation coincide in shape and size with the dents found on real pipelines, which confirms the nature of the formation of dents due to the static effect of the pipe's own weight and the weight of the filling soil Trench ; Pipeline transport ; Base (topology) ; Action (physics) ; Process (computing) ; Mechanism (biology) ; Stress (linguistics) Material Properties and Failure Mechanisms ; Structural Integrity and Reliability Analysis ; Engineering Diagnostics and Reliability
Authors: N. Yu. Filonenko | Liudmyla Bartashevska | Oleksandra Haldina
Source: E3S Web of Conferences (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Improvement of mechanical and operational steel characteristics by strengthening the surface The growing demands in the mining industry require steel products capable of withstanding heavy loads. To achieve enhanced mechanical, service, and operational properties in steel, common methods include adjusting carbon content, optimizing primary element concentrations, and applying expensive microalloying and heat treatments. For metal products operating under high vibration or as contact pairs, surface layer strengthening is essential. This study investigates the relationship between the composition of the saturating medium, the degree of cold plastic deformation, and the effects of saturation regimes on the structure, mechanical, and service properties of low-carbon steel. Samples were analyzed after annealing and cold plastic deformation using metallographic analysis, mechanical and tribological testing, X-ray diffraction, and chemical and X-ray spectral analysis. The results indicate that cold plastic deformation enhances the diffusion mobility of boron and carbon. To produce effective boron-cemented surface layers, a saturating mixture with up to 4.5% boron carbide is recommended. These boron-cemented layers, containing phases such as Fe 2 B, Fe 3 (CB), and Fe 23 (CB) 6 , exhibit strong adhesion to the matrix and superior mechanical and tribological properties. The boron-bearing phases are partially located along grain boundaries and within grains. This method allows for boron-cemented layers up to 2.0 – 2.3 mm deep, nearly double the depth achieved by traditional cementation methods, offering significant potential for strengthening steel products in the mining industry. Materials science Metal Alloys Wear and Properties ; Material Properties and Failure Mechanisms ; Material Properties and Applications
Authors: Flaviano Della Pia | Andrea Zen | Dario Alfè | Angelos Michaelides
Source: arXiv (Cornell University) (preprint, 2024-02-20)
Field: Chemistry — Inorganic Chemistry

How accurate are simulations and experiments for the lattice energies of molecular crystals? Molecular crystals play a central role in a wide range of scientific fields, including pharmaceuticals and organic semiconductor devices. However, they are challenging systems to model accurately with computational approaches because of a delicate interplay of intermolecular interactions such as hydrogen bonding and van der Waals dispersion forces. Here, by exploiting recent algorithmic developments, we report the first set of diffusion Monte Carlo lattice energies for all 23 molecular crystals in the popular and widely used X23 dataset. Comparisons with previous state-of-the-art lattice energy predictions (on a subset of the dataset) and a careful analysis of experimental sublimation enthalpies reveals that high-accuracy computational methods are now at least as reliable as (computationally derived) experiments for the lattice energies of molecular crystals. Overall, this work demonstrates the feasibility of high-level explicitly correlated electronic structure methods for broad benchmarking studies in complex condensed phase systems, and signposts a route towards closer agreement between experiment and simulation. Lattice (music) ; Lattice energy ; Statistical physics ; Materials science ; Condensed matter physics ; Chemical physics ; Crystallography ; Physics ; Crystal structure ; Chemistry Inorganic Fluorides and Related Compounds ; Organic and Molecular Conductors Research ; Inorganic Chemistry and Materials
Authors: Shaw-Guang Huang
Source: Highlights in Science Engineering and Technology (article, 2024-12-24)
Field: Materials Science — Polymers and Plastics

Research Status and Optimization of Small Molecule Organic Solar Cells Organic solar cells, particularly those made from small molecule materials, have garnered significant attention in recent years due to their numerous advantages. One of the most notable benefits is their clear material molecular structures, which allow for precise regulation of energy levels. This clarity also extends to purification methods, which are simple and straightforward. Additionally, small molecule materials are highly adaptable and can be used in a variety of applications, ranging from building-integrated photovoltaics to wearable devices. This article delves deeper into the development status and application prospects of organic solar cell technology, with a particular emphasis on the benefits of small molecule materials and their manufacturing processes. By examining the potential applications of organic solar cells in different fields, this article provides valuable insights and guidance for those interested in studying and applying organic solar cell technology. Overall, this article highlights the exciting opportunities that exist for the advancement of clean energy technology through the use of organic solar cells. Organic solar cell ; Small molecule ; Organic molecules ; Molecule ; Materials science ; Environmental science ; Chemistry ; Organic chemistry ; Biochemistry ; Polymer Conducting polymers and applications ; Organic Electronics and Photovoltaics
Authors: Н.А. Клычков | В.В. Симаков | И.В. Синёв
Source: Physical and Chemical Aspects of the Study of Clusters Nanostructures and Nanomaterials (article, 2024-12-15)
Field: Materials Science — Materials Chemistry

Влияние глубоких поверхностных акцепторных состояний на температурную зависимость проводимости слоёв оксида цинка An experimental and theoretical study was conducted on the temperature dependence of the conductivity of zinc oxide (ZnO) layers in dry air and ethanol. The study found that the conductivity of ZnO depends non-linearly on temperature, and its type varies depending on experimental conditions. Scanning speed directly affects the type of the temperature dependence, with a local minimum in conductivity between 250±5°C at a scanning rate of 0,4°C/min. However, monotonic dependencies are observed at slower scanning rates, such as 30°C/min, and a mechanism is proposed to explain the effect of the scanning velocity on the type of dependency. This mechanism involves the process of the thermal activation of oxygen molecules to form atomic oxygen at adsorption sites. The key idea behind this mechanism is that atomic oxygen forms deeper acceptor levels on zinc oxide surfaces compared to molecular oxygen. At a high scanning rate, the relaxation time for filling the surface with adsorbed oxygen is significantly longer than the experimental time. Therefore, metastable «frozen» states of atomic forms of adsorbed oxygen appear on the surface of zinc oxide layers. As a result, metastable «frozen» states of adsorbed atoms appear on the surface of zinc oxide layers. Based on calculations using this model, we propose a method for reducing the number of nonequilibrium atomic oxygen states by heating samples in a reducing medium. Medicine ZnO doping and properties ; Gas Sensing Nanomaterials and Sensors ; Silicone and Siloxane Chemistry
Authors: Azat Abdullaev | Kairolla Sekerbayev | Alexander Azarov | Vishnukanthan Venkatachalapathy | Vinay Chauhan | Zhandos Utegulov | Andrej Kuznetsov
Source: arXiv (Cornell University) (preprint, 2024-06-06)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Thermal Conductivity of Double Polymorph Ga2O3 Structures Recently discovered double gamma/beta (γ/\b{eta}) polymorph Ga2O3 structures constitute a class of novel materials providing an option to modulate functional properties across interfaces without changing chemical compositions of materials, in contrast to that in conventional heterostructures. In this work, for the first time, we investigate thermal transport in such homo-interface structures as an example of their physical properties. Specifically, the cross-plane thermal conductivity (k) was measured by femtosecond laser-based time-domain thermoreflectance with MHz modulation rates, effectively obtaining depth profiles of the thermal conductivity across the γ/\b{eta}-Ga2O3 structures. In this way, the thermal conductivity of γ-Ga2O3 k=1.84÷2.11 W m-1K-1 was found to be independent of the initial \b{eta}-substrates orientations, in accordance with the cubic spinel structure of the γ-phase and consistently with the molecular dynamics simulation data. In its turn, the thermal conductivity of monoclinic \b{eta}-Ga2O3 showed a distinct anisotropy, with values ranging from 10 W m-1K-1 for [201] to 20 Wm-1K-1 for [010] orientations. Thus, for double γ/\b{eta} Ga2O3 polymorph structures formed on [010] \b{eta}-substrates, there is an order of magnitude difference in thermal conductivity across the γ/\b{eta} interface, which potentially can be exploited in thermal energy conversion applications. Thermal conductivity ; Materials science ; Conductivity ; Crystallography ; Composite material ; Chemistry ; Physical chemistry Ga2O3 and related materials ; Magnesium Oxide Properties and Applications ; Advanced Photocatalysis Techniques
Authors: Hujun Cao | Bin Li
Source: arXiv (Cornell University) (preprint, 2024-12-30)
Field: Chemistry — Spectroscopy

EdSr: A Novel End-to-End Approach for State-Space Sampling in Molecular Dynamics Simulation The molecular dynamics (MD) simulation technique has been widely used in complex systems, but the accessible time scale is limited due to the requirement of small integration timesteps. Here, we propose a novel method, named Exploratory dynamics Sampling with recursion (EdSr), inspired by ordinary differential equation and Taylor expansion formula, which enables flexible adjustment of timestep in MD simulations. By setting up four groups of experiments including simple functions, ideal physical models, all-atom simulations and coarse-grained simulations, we demonstrate that EdSr can dynamically and flexibly adjust the simulation timestep according to the requirements during simulation period, and operate with larger timesteps than the widely used velocity-Verlet integrator. Although the method can not perform perfectly at flexible timestep across all simulation systems, we believe that it provides a promising direction for future studies. End-to-end principle ; Sampling (signal processing) ; State space ; Computer science ; Dynamics (music) ; State (computer science) ; Statistical physics ; Mathematics ; Physics ; Algorithm ; Artificial intelligence ; Telecommunications ; Statistics Mass Spectrometry Techniques and Applications ; Spectroscopy and Quantum Chemical Studies ; Machine Learning in Materials Science
Authors: Jianping Li
Source: Systems and Control Transactions (article, 2024-07-09)
Field: Materials Science — Materials Chemistry

Learning Hybrid Extraction and Distillation using Phenomena-based String Representation We present a string representation for hybrid extraction and distillation using symbols representing phenomena building blocks. Unlike the conventional equipment-based string representation, the proposed representation captures the design details of liquid-liquid extraction and distillation. We generate a set of samples through the procedure of input parameter sampling and superstructure optimization that minimizes separation cost. We convert these generated samples into a set of string representations based on pre-defined rules. We use these string representations as descriptors and connect them with conditional variational encoder. The trained conditional variational encoder shows good prediction accuracy. We further use the trained conditional variational encoder to screen designs of hybrid extraction and distillation with desired cost investment. Computer science ; Extraction (chemistry) ; Representation (politics) ; Distillation ; String (physics) ; Artificial intelligence ; Machine learning ; Chemistry ; Chromatography ; Physics ; Theoretical physics Crystallization and Solubility Studies ; Advanced Control Systems Optimization ; Fluid Dynamics and Mixing
Authors: Ronit Eshel | David Fuks | Yaniv Gelbstein | Daniel Rabin
Source: Physical Chemistry Chemical Physics (article, 2024-11-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

The effect of acceptor and donor doping on the electronic properties of the half-Heusler TiNiSn Optimizing the electronic transport properties of thermoelectric compounds is commonly achieved by either donor or acceptor atom doping to increase the conduction of the appropriate carrier type, electrons or holes, respectively. Enhancing carrier mobility and carrier concentration will both lead to optimized electronic properties. In this work the effect of various dopants on the electronic properties of TiNiSn was explored, by modeling the doping of an ideal compound on the Ti-sublattice with acceptor or donor elements. Using <i>ab initio</i> DFT calculations and a set of analytical expressions of transport properties, the temperature dependencies of the electronic properties were calculated, to examine possible n-type or p-type dopants to be used in further experimental studies. Doping ; Acceptor ; Materials science ; Electron ; Thermoelectric effect ; Thermal conduction ; Condensed matter physics ; Conduction band ; Optoelectronics ; Physics ; Thermodynamics Heusler alloys: electronic and magnetic properties ; Advanced Thermoelectric Materials and Devices ; Semiconductor materials and interfaces
Source: Physical Chemistry Chemical Physics (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Contents list Permissions Request permissions Contents list Phys. Chem. Chem. Phys., 2024, 26, 1469 DOI: 10.1039/D4CP90012J This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given. Read more about how to correctly acknowledge RSC content. Acknowledgement ; Chromatin structure remodeling (RSC) complex ; Computer science ; Attribution ; Information retrieval ; Chemistry ; Computer security ; Psychology Luminescence Properties of Advanced Materials ; Quantum Dots Synthesis And Properties
Authors: Umit Volkan Ucak | Islambek Ashyrmamatov | Juyong Lee
Source: ChemRxiv (preprint, 2024-01-17)
Field: Chemistry — Spectroscopy

Refining EI-MS library search results through atomic-level insights Mass spectral reference libraries are fundamental tools for compound identification in electron-ionization mass spectrometry (EI-MS). However, the inherent complexity of mass spectra and the lack of direct correlation between spectral and structural similarities present significant challenges in structure elucidation and accurate peak annotation. To address these challenges, we have introduced an approach combining CFM-EI, a fragmentation likelihood modeling tool in EI-MS data, with a multi-step complexity reduction strategy for mass-to-fragment mapping. Our methodology involves employing modified atomic environments to represent fragment ions of super small organic molecules and training a transformer model to predict the structural content of compounds based on mass and intensity data. This holistic solution not only aids in interpreting EI-MS data by providing insights into atom types but also refines cosine similarity rankings by suggesting inclusion or exclusion of specific atom types. Tests conducted on EI-MS data from the NIST database demonstrated that our approach complements conventional methods by improving spectra matching through an in-depth atomic-level analysis. Fragmentation (computing) ; NIST ; Mass spectrum ; Atomic mass ; Chemistry ; Mass spectrometry ; Data mining ; Computer science ; Analytical Chemistry (journal) ; Atomic physics ; Physics ; Chromatography ; Natural language processing Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Isotope Analysis in Ecology
Authors: Yibo Zhang | Suman Itani | Kamal Khanal | Emmanuel Okyere | Gavin Smith | Koichiro Takahashi | Jiadong Zang
Source: arXiv (Cornell University) (preprint, 2024-01-11)
Field: Materials Science — Materials Chemistry

GPTArticleExtractor: An Automated Workflow for Magnetic Material Database Construction A comprehensive database of magnetic materials is valuable for researching the properties of magnetic materials and discovering new ones. This article introduces a novel workflow that leverages large language models for extracting key information from scientific literature. From 22,120 articles in the Journal of Magnetism and Magnetic Materials, a database containing 2,035 magnetic materials was automatically generated, with ferromagnetic materials constituting 76% of the total. Each entry in the database includes the material's chemical compounds, as well as related structures (space group, crystal structure) and magnetic temperatures (Curie, N'eel, and other transitional temperatures). To ensure data accuracy, we meticulously compared each entry in the database against the original literature, verifying the precision and reliability of each entry. Workflow ; Magnetism ; Ferromagnetism ; Database ; Computer science ; Curie temperature ; Physics ; Condensed matter physics Machine Learning in Materials Science ; Topic Modeling ; Scientific Computing and Data Management
Authors: Shuang Lin | Shun‐Li Shang | Allison M. Beese | Zi‐Kui Liu
Source: arXiv (Cornell University) (preprint, 2024-03-01)
Field: Materials Science — Materials Chemistry

Temperature-dependent thermodynamic properties of CrNbO4 and CrTaO4 by first-principles calculations In the present work, the density functional theory (DFT) in the generalized-gradient approximation developed by Perdew, Burke, and Ernzerhof (PBE) +U method, i.e., PBE+U, was employed to predict temperature-dependent thermodynamic properties of the rutile-type oxides CrNbO4 and CrTaO4 as well as the binary oxides Cr2O3, Nb2O5, and Ta2O5 via the quasiharmonic phonon approach (QHA). Calculated thermodynamic properties of the binary oxides were benchmarked with experimental data, showing high accuracy except for the negative thermal expansion (NTE) of Nb2O5, attributed to its polymorphic complexity. By combining the formation energy predicted by DFT with the existing SGTE Substances Database (SSUB5), the CrNbO4 and CrTaO4 are found to be thermodynamic stable up to 1706 K and 1926 K and decompose into Cr2O3 and Nb2O5 or Ta2O5 at those temperatures, respectively. The temperature dependence of linear thermal expansion coefficients for CrNbO4 and CrTaO4 are predicted, and their mean values from 500 K to 2000 K are found to be 6.0*10-6/K and 5.04*10-6/K, respectively, in agreement with experimental observations in the literature. The gas-phase species and their vapor pressure are calculated, indicating that the formation of CrTaO4 and CrNbO4 reduces chromium volatilization, which is critically important to design enhanced Refractory high entropy alloys (RHEAs) with enhanced oxidation resistance. Epistemology ; Statistical physics ; Mathematical economics ; Thermodynamics ; Mathematics ; Physics ; Philosophy Nuclear materials and radiation effects ; Metallurgical Processes and Thermodynamics ; Thermal and Kinetic Analysis
Authors: Christopher L. Rom | Matthew Jankousky | Manh‐Huong Phan | Shaun O’Donnell | C. Regier | James R. Neilson | Vladan Stevanović | Andriy Zakutayev
Source: arXiv (Cornell University) (preprint, 2024-12-03)
Field: Materials Science — Materials Chemistry

Ion exchange synthesizes layered polymorphs of MgZrN$_2$ and MgHfN$_2$, two metastable semiconductors The synthesis of ternary nitrides is uniquely difficult, in large part because elemental N$_2$ is relatively inert. However, lithium reacts readily with other metals and N$_2$, making Li-M-N the most numerous sub-set of ternary nitrides. Here, we use Li$_2$ZrN$_2$, a ternary with a simple synthesis recipe, as a precursor for ion exchange reactions towards AZrN$_2$ (A = Mg, Fe, Cu, Zn). In situ synchrotron powder X-ray diffraction studies show that Li$^+$ and Mg$^{2+}$ undergo ion exchange topochemically, preserving the layers of octahedral [ZrN$_6$] to yield a metastable layered polymorph of MgZrN$_2$ (spacegroup $R\overline{3}m$) rather than the calculated ground state structure ($I41/amd$). UV-vis measurements show an optical absorption onset near 2.0 eV, consistent with the calculated bandgap for this polymorph. Our experimental attempts to extend this ion exchange method towards FeZrN$_2$, CuZrN$_2$, and ZnZrN$_2$ resulted in decomposition products (A + ZrN + 1/6 N$_2$), an outcome that our computational results explain via the higher metastability of these phases. We successfully extended this ion exchange method to other Li-M-N precursors by synthesizing MgHfN$_2$ from Li$_2$HfN$_2$. In addition to the discovery of metastable $R\overline{3}m$ MgZrN$_2$ and MgHfN$_2$, this work highlights the potential of the 63 unique Li-M-N phases as precursors to synthesize new ternary nitrides. Metastability ; Semiconductor ; Ion ; Materials science ; Ion exchange ; Crystallography ; Chemistry ; Optoelectronics ; Organic chemistry MXene and MAX Phase Materials ; Inorganic Chemistry and Materials ; Boron and Carbon Nanomaterials Research