jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Atef Korchef | Imen Souid
Source: Crystals (article, 2023-07-26)
Field: Materials Science — Materials Chemistry

Grain Refinement and Strengthening of an Aluminum Alloy Subjected to Severe Plastic Deformation through Equal-Channel Angular Pressing In the present study, the microstructure, mechanical properties, and stored energy of an aluminum alloy containing iron-rich fine precipitates, subjected to severe plastic deformation through equal-channel angular pressing (ECAP), were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Up to four passes through ECAP resulted in significant nanometer-scale grain refinement, as well as the accumulation of lattice defects, such as dislocations and mesoscopic shear planes. This resulted in a noticeable enhancement in the Vickers microhardness and the flow stress after ECAP. Differential scanning calorimetry results showed that the ECAP’ed material exhibited two exothermal peaks at 222 ± 2 °C and 362 ± 2 °C, with total thermal effects of ΔH = 4.35 and 6.5 J/g, respectively. Slight increases in the ECAP’ed material microhardness and flow stress were observed at 200 °C. The heat release, at a relatively low temperature, and the slight improvement in the mechanical properties were attributed to the evolution of low- and high-angle misorientation, with the strain and the pinning of tangled dislocation caused by the existing fine particles. The second peak was attributed to grain growth, resulting in a significant softening of the material. Materials science ; Severe plastic deformation ; Indentation hardness ; Microstructure ; Flow stress ; Metallurgy ; Alloy ; Grain size ; Composite material ; Scanning electron microscope ; Dislocation ; Differential scanning calorimetry ; Misorientation ; Grain boundary Microstructure and mechanical properties ; Aluminum Alloys Composites Properties ; Aluminum Alloy Microstructure Properties
Authors: Ebubekir Sıddık Aydın | Ibrahim Korkut
Source: Journal of Polytechnic (article, 2023-04-02)
Field: Materials Science — Biomaterials

Statistical Modelling of Process Variables in the Electrospinning Production of PAN-Based Nanofibers In this study, the effects of the electrospinning operating parameters such as flow rate (1-5 ml/h), voltage (15-30 kV), and distance to the collector (100-200 mm) on the physical properties of PAN-based nanofibers were investigated statistically by applying the central composite design method. The minimum nanofiber diameter was found to be 366.5 nm, under operating conditions of 5 ml/h flow rate, 30 kV, and 100 mm distance to the collector. Experimental conditions of 15 kV, 5 ml/h flow rate, and a 200 mm distance to the collector, a maximum porosity value of 0.446 was obtained. Similarly to the porosity, the water absorption capacity (WAC) value did not show a linear increase, and the maximum absorption capacity was calculated as 5712%, and at that point where the diameter is relatively large and the porosity is low. Porosity ; Materials science ; Volumetric flow rate ; Absorption of water ; Absorption (acoustics) ; Composite material ; Electrospinning ; Nanofiber ; Composite number ; Absorption rate ; Analytical Chemistry (journal) ; Chemistry ; Chromatography ; Physics ; Thermodynamics ; Polymer Electrospun Nanofibers in Biomedical Applications ; Supercapacitor Materials and Fabrication ; Conducting polymers and applications
Authors: Pengxiang Tang | Hongting Li | Xiaomei Zhang | Xin Sun
Source: RSC Advances (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

A mathematical model of catalyst combination design and temperature control in the preparation of C<sub>4</sub> olefins through ethanol coupling The preparation of C<sub>4</sub> olefins through ethanol catalytic coupling is a crucial area of study. According to the experimental data obtained by a chemical laboratory for different catalysts at different temperatures, three mathematical models were developed to provide insights into the relationships among ethanol conversion rate, C<sub>4</sub> olefins selectivity, yield, catalyst combination, and temperature. The first model is a nonlinear fitting function that analyses the relationships among ethanol conversion rate, C<sub>4</sub> olefins selectivity, and temperature under varying catalyst combinations. Two-factor analysis of variance was employed to determine the influence of catalyst combinations and temperatures on ethanol conversion rate and C<sub>4</sub> olefins selectivity. The second model is a multivariate nonlinear regression model that describes the relationships among the yield of C<sub>4</sub> olefins, catalyst combination, and temperature. Finally, an optimization model was derived based on the experimental conditions; it provides a solution for the selection of the optimal catalyst combinations and temperatures to achieve the maximum yield of C<sub>4</sub> olefins. This work has significant implications for the field of chemistry and the production of C<sub>4</sub> olefins. Selectivity ; Catalysis ; Yield (engineering) ; Ethanol ; Chemistry ; Coupling (piping) ; Chemical engineering ; Materials science ; Organic chemistry Zeolite Catalysis and Synthesis ; Catalysis and Oxidation Reactions ; Catalysis for Biomass Conversion
Authors: Aviv Navon | Aviv Shamsian | Idan Achituve | Ethan Fetaya | Gal Chechik | Haggai Maron
Source: arXiv (Cornell University) (preprint, 2023-01-30)
Field: Materials Science — Materials Chemistry

Equivariant Architectures for Learning in Deep Weight Spaces Designing machine learning architectures for processing neural networks in their raw weight matrix form is a newly introduced research direction. Unfortunately, the unique symmetry structure of deep weight spaces makes this design very challenging. If successful, such architectures would be capable of performing a wide range of intriguing tasks, from adapting a pre-trained network to a new domain to editing objects represented as functions (INRs or NeRFs). As a first step towards this goal, we present here a novel network architecture for learning in deep weight spaces. It takes as input a concatenation of weights and biases of a pre-trained MLP and processes it using a composition of layers that are equivariant to the natural permutation symmetry of the MLP's weights: Changing the order of neurons in intermediate layers of the MLP does not affect the function it represents. We provide a full characterization of all affine equivariant and invariant layers for these symmetries and show how these layers can be implemented using three basic operations: pooling, broadcasting, and fully connected layers applied to the input in an appropriate manner. We demonstrate the effectiveness of our architecture and its advantages over natural baselines in a variety of learning tasks. Equivariant map ; Concatenation (mathematics) ; Computer science ; Pooling ; Permutation (music) ; Invariant (physics) ; Deep learning ; Affine transformation ; Artificial intelligence ; Artificial neural network ; Theoretical computer science ; Arithmetic ; Mathematics ; Pure mathematics Machine Learning in Materials Science ; Neural Networks and Applications ; Machine Learning in Bioinformatics
Authors: Ebrahim Mansouri | Pär Olsson
Source: Physical Review Materials (article, 2023-12-21)
Field: Materials Science — Materials Chemistry

Microstructure and magnetization evolution in bcc iron via direct first-principles predictions of radiation effects We here model the radiation-induced microstructure evolution in bcc iron using the creation-relaxation algorithm directly driven by density functional theory calculations and compare to interatomic potential simulations. The method is in essence a relatively simplified model without thermally driven diffusion. The microstructure evolution in this model is driven mostly by the stress field introduced by sequential direct damage insertions. The defect populations and the corresponding defect cluster characteristics have been analyzed as a function of irradiation dose. Different distribution functions have been investigated for the self-interstitial atom implantation, to make model predictions as close as possible to actual irradiation conditions under which defects are produced. The stability and magnetic characteristics of the defect structures that are formed are studied. Our first-principles simulations revealed that the C15 structure can be dynamically formed during the irradiation of the material and that the constituent atoms align antiferromagnetically to the lattice. For doses on the order of a fraction of 1 displacement per atom, the model material Fe experiences mechanical changes caused by continuous irradiation and approaches a saturation state of about 2% swelling. The radiation-induced change in the local magnetic moments as well as the charge density differences for some isolated and clustered defects have been investigated. The results revealed a net reduction in total magnetization per atom and a tendency for interstitial sites to have a spin polarization opposing the intrinsic atomic site spins when the coordination number was increased compared to that of the initial lattice structure. It is suggested that radiation-induced damage could be traced using nondestructive measures of bulk magnetization changes. Materials science ; Microstructure ; Irradiation ; Atom (system on chip) ; Magnetization ; Condensed matter physics ; Frenkel defect ; Spallation ; Molecular physics ; Molecular dynamics ; Spins ; Coordination number ; Density functional theory ; Chemical physics ; Crystallographic defect ; Magnetic field ; Neutron ; Computational chemistry ; Composite material ; Chemistry ; Physics Fusion materials and technologies ; Nuclear Materials and Properties ; Microstructure and mechanical properties
Authors: Benjamin Geisler | J. J. Hamlin | G. R. Stewart | Richard G. Hennig | P. J. Hirschfeld
Source: arXiv (Cornell University) (preprint, 2023-09-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Structural transitions, octahedral rotations, and electronic properties of $A_3$Ni$_2$O$_7$ rare-earth nickelates under high pressure Motivated by the recent observation of superconductivity with $T_c \sim 80$ K in pressurized La3Ni2O7 [Nature 621, 493 (2023)], we explore the structural and electronic properties in A3Ni2O7 bilayer nickelates (A=La-Lu, Y, Sc) as a function of hydrostatic pressure (0-150 GPa) from first principles including a Coulomb repulsion term. At $\sim 20$ GPa, we observe an orthorhombic-to-tetragonal transition in La$_3$Ni$_2$O$_7$ at variance with recent x-ray diffraction data, which points to so-far unresolved complexities at the onset of superconductivity, e.g., charge doping by variations in the oxygen stoichiometry. We compile a structural phase diagram with particular emphasis on the $b/a$ ratio, octahedral anisotropy, and octahedral rotations. Intriguingly, chemical and external pressure emerge as two distinct and counteracting control parameters. We find unexpected correlations between $T_c$ and the in-plane Ni-O-Ni bond angles for La$_3$Ni$_2$O$_7$. Moreover, two novel structural phases with significant $c^+$ octahedral rotations and in-plane bond disproportionations are uncovered for A=Nd-Lu, Y, Sc that exhibit a surprising pressure-driven electronic reconstruction in the Ni $e_g$ manifold. By disentangling the involvement of basal versus apical oxygen states at the Fermi surface, we identify Tb$_3$Ni$_2$O$_7$ as an interesting candidate for superconductivity at ambient pressure. These results suggest a profound tunability of the structural and electronic phases in this novel materials class and are key for a fundamental understanding of the superconductivity mechanism. Superconductivity ; Condensed matter physics ; Hydrostatic pressure ; Octahedron ; Materials science ; Tetragonal crystal system ; Crystallography ; Orthorhombic crystal system ; Ambient pressure ; Anisotropy ; Physics ; Chemistry ; Thermodynamics ; Crystal structure Magnetic and transport properties of perovskites and related materials ; Electronic and Structural Properties of Oxides ; Advanced Condensed Matter Physics
Authors: Romain Botella | J. Catalá | Wei Cao
Source: Materials Letters (article, 2023-09-01)
Field: Materials Science — Materials Chemistry

Experimental Ni3TeO6 synthesis condition exploration accelerated by active learning Material synthesis is time- and chemicals-consuming due to the traditional (“brute force”) methodology. For instance, Ni3TeO6 (NTO) is a multiferroic material relevant in different applications. Herein, we used an active learning scheme to explore the different phases obtained using a complex hydrothermal synthesis procedure instead of a solid-state methodology. Different from conventional ML prediction requiring a large dataset, we show that with only 9 data points obtained through experimental endeavor, 87% of the experimental condition space is predicted. The predicted phase configuration is verified with the sample in a new synthetic work. Beside exploring the NTO species, scheme developed herein constitute a powerful tool for experimental condition optimization. Materials science ; Scheme (mathematics) ; Multiferroics ; Hydrothermal circulation ; Hydrothermal synthesis ; Phase (matter) ; Computer science ; Experimental data ; Sample (material) ; Nanotechnology ; Biological system ; Chemical engineering ; Thermodynamics ; Mathematics ; Engineering ; Physics Machine Learning in Materials Science ; Advanced Memory and Neural Computing ; Ferroelectric and Negative Capacitance Devices
Authors: Zi Hao Liu | Oufan Zhang | João M. C. Teixeira | Jie Li | Teresa Head‐Gordon | Julie D. Forman‐Kay
Source: The Journal of Open Source Software (article, 2023-05-10)
Field: Materials Science — Materials Chemistry

SPyCi-PDB: A modular command-line interface forback-calculating experimental datatypes of protein structures. Liu et al., (2023). SPyCi-PDB: A modular command-line interface for back-calculating experimental datatypes of protein structures.. Journal of Open Source Software, 8(85), 4861, https://doi.org/10.21105/joss.04861 Modular design ; Interface (matter) ; Protein Data Bank (RCSB PDB) ; Computer science ; Programming language ; Software ; Line (geometry) ; Computational science ; Operating system ; Chemistry ; Mathematics ; Geometry ; Stereochemistry Enzyme Structure and Function ; Protein Structure and Dynamics ; Metabolomics and Mass Spectrometry Studies
Authors: Gedefaw Mebratie | Tigabu Bekele
Source: Advances in Condensed Matter Physics (article, 2023-08-29)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Theoretical Investigation of the Interplay of Superconductivity and Magnetism in Ba1−xKxFe2As2 Superconductor in a Two-Band Model by Using the Bogoliubov Transformation Formalism The main focus of this article is to investigate the theoretical interplay of magnetism and superconductivity in a two-band model for the iron-based superconductor Ba1−xKxFe2As2. On the basis of experimental results, the two-band model Hamiltonian was considered. We obtained mathematical statements for the superconductor Ba1−xKxFe2As2 superconducting (SC) transition temperature, spin-density-wave (SDW), transition temperature, superconductivity order parameter, and SDW order parameter from the Bogoliubov transformation formalism and the model Hamiltonian. Furthermore, an expression for the dependence of the SDW transition temperature on the SDW order parameter and the dependence of the SC transition temperature on the SDW order parameter was obtained for Ba1−xKxFe2As2. By substituting the experimental and theoretical values of the parameters in the derived statements, phase diagrams of the SC transition temperature versus the SDW order parameter and the SDW transition temperature versus the SDW order parameters have been plotted to demonstrate the dependence of the SDW order parameter on transition temperatures. By combining the two-phase diagrams, we depicted the possible coexistence of superconductivity and magnetism for the Ba1−xKxFe2As2 superconductor. The phase diagrams of temperature versus SC order parameter and temperature versus SDW order parameter were also plotted to show the dependence of order parameters on temperature for the Ba1−xKxFe2As2 superconductor. Superconductivity ; Condensed matter physics ; Magnetism ; Hamiltonian (control theory) ; Physics ; Phase diagram ; Formalism (music) ; Phase transition ; Transition temperature ; Superconducting transition temperature ; Materials science ; Phase (matter) ; Quantum mechanics ; Mathematics Iron-based superconductors research ; Intellectual Capital and Performance Analysis ; Physics of Superconductivity and Magnetism
Authors: Sravanthi Gandu | Kumaraswamy Gandla | M Vaishnavi | Lalitha Repudi
Source: World Journal of Advanced Research and Reviews (review, 2023-05-16)
Field: Chemistry — Analytical Chemistry

A review on implementation of automation in the pharmaceutical industries Automation is the use of various control systems in industries with little to no human intervention to carry out a variety of tasks. In recent years, automation has migrated to the pharmaceutical sector. Production, packing, labeling, and warehousing departments have all used automation. The use of automated equipment has made the production of customized medications a reality. Using the newest technologies has also had an impact on the R&amp;D sector. The traditional duties of the QA department were restricted to creating SOPs, conducting audits, qualifying, and validating processes and equipment. The deployment of automated technology in the pharmaceutical sector and its effects on the department responsible for pharmaceutical quality assurance are the main topics of this research. The Raman probe and other subjects are covered in this article. Production, packing, labeling, and warehousing departments have all used automation. After the introduction of automated machinery, the creation of customized medications has come to pass. Thus, these systems might be able to take the place of human inspectors. With this technology, you have more flexibility and repeatability for less money. Automation ; Flexibility (engineering) ; Audit ; Production (economics) ; Quality assurance ; Software deployment ; Manufacturing engineering ; Pharmaceutical industry ; Engineering management ; Business ; Quality (philosophy) ; Operations management ; Computer science ; Process management ; Risk analysis (engineering) ; Engineering ; Marketing ; Medicine ; Service (business) ; Software engineering ; Management ; Accounting ; Pharmacology Analytical Methods in Pharmaceuticals ; Spectroscopy and Chemometric Analyses ; Pharmaceutical Quality and Counterfeiting
Authors: Tjaša Rijavec | Dominika Pawcenis | Krzysztof Kruczała | Matija Strlič | Irena Kralj Cigić
Source: Heritage Science (article, 2023-07-27)
Field: Materials Science — Polymers and Plastics

The significance of sample preparation of historical and contemporary poly(vinyl chloride) objects to investigate the distribution and changes of molar mass by SEC-MALS-dRI Abstract The distribution of molar mass of historical and contemporary poly(vinyl chloride) objects was determined using size exclusion chromatography with multi-angle light scattering detection. The weight average molar mass was determined for a collection of 57 samples, ranging from 75 to 186 kg/mol with a median of 102 kg/mol. Rigid PVC objects were found to have a significantly lower weight average molar mass (M w = 81 kg/mol) than plasticized ones (M w = 102 kg/mol). Thin objects also exhibited significantly lower M w than bulky objects. A substantial presence of aggregates was noted and characterized as an ‘aggregate ratio’ for the entire collection. Heating a solution of poly(vinyl chloride) in THF at 55 °C for 5 h proved successful in the dissociation of the aggregates and allowed for an accurate determination of molar mass. The uncertainty of the M w determination was statistically evaluated and used to study the effects of accelerated degradation on M w . No statistically significant changes in M w were observed in samples artificially aged at 50 °C to 80 °C for up to 15 weeks, indicating that M w does not decrease during degradation of a PVC heritage object and that accelerated degradation does not lead to polymer crosslinking. Molar mass ; Size-exclusion chromatography ; Molar mass distribution ; Molar ; Vinyl chloride ; Chemistry ; Polymer ; Molecular mass ; Polymer chemistry ; Dissociation (chemistry) ; Degradation (telecommunications) ; Molar ratio ; Gel permeation chromatography ; Analytical Chemistry (journal) ; Nuclear chemistry ; Chromatography ; Copolymer ; Organic chemistry ; Catalysis ; Geology Polymer Science and PVC ; Recycling and Waste Management Techniques ; Extraction and Separation Processes
Authors: A. V. Scherbakov | T. L. Linnik | S. M. Kukhtaruk | D. R. Yakovlev | Achim Nadzeyka | A. W. Rushforth | А. В. Акимов | M. Bayer
Source: Photoacoustics (review, 2023-10-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Ultrafast magnetoacoustics in Galfenol nanostructures Phonons and magnons are prospective information carriers to substitute the transfer of charge in nanoscale communication devices. Our ability to manipulate them at the nanoscale and with ultimate speed is examined by ultrafast acoustics and femtosecond optomagnetism, which use ultrashort laser pulses for generation and detection of the corresponding coherent excitations. Ultrafast magnetoacoustics merges these research directions and focuses on the interaction of optically generated coherent phonons and magnons. In this review, we present ultrafast magnetoacoustic experiments with nanostructures based on the alloy (Fe,Ga) known as Galfenol. We demonstrate how broad we can manipulate the magnetic response on an optical excitation by controlling the spectrum of generated coherent phonons and their interaction with magnons. Resonant phonon pumping of magnons, formation of magnon polarons, driving of a magnetization wave by a guided phonon wavepacket are demonstrated. The presented experimental results have great application potential in emerging areas of modern nanoelectronics. Magnon ; Ultrashort pulse ; Phonon ; Femtosecond ; Condensed matter physics ; Excitation ; Materials science ; Polaron ; Nanoscopic scale ; Optoelectronics ; Terahertz radiation ; Laser ; Physics ; Nanotechnology ; Ferromagnetism ; Optics Magnetic Properties and Applications ; Magnetic properties of thin films ; Magneto-Optical Properties and Applications