jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Dao Trinh | Alexis Renaud | Julien Valette | S. Mallarino | S. Touzain
Source: Electrochimica Acta (article, 2023-07-27)
Field: Chemistry — Electrochemistry

Measurement of water profiles released from composite material by using the SECM technique Scanning electrochemical microscopy ; Microelectrode ; Composite number ; Electrochemistry ; Materials science ; Polymer ; Analytical Chemistry (journal) ; Electrode ; Ionic liquid ; Ionic bonding ; Microscopy ; Chemical engineering ; Chemistry ; Composite material ; Chromatography ; Ion ; Optics ; Organic chemistry Electrochemical Analysis and Applications ; Ionic liquids properties and applications ; Advanced Chemical Sensor Technologies
Authors: Juan Matos | Claudia Patricia Amézquita-Marroquín | Johan D. Lozano | Jhon Zapata‐Rivera | Liliana Giraldo | Po S. Poon | Juan Carlos Moreno‐Piraján
Source: Molecules (article, 2023-07-07)
Field: Materials Science — Materials Chemistry

Experimental and Theoretical Estimations of Atrazine’s Adsorption in Mangosteen-Peel-Derived Nanoporous Carbons Nanoporous carbons were prepared via chemical and physical activation from mangosteen-peel-derived chars. The removal of atrazine was studied due to the bifunctionality of the N groups. Pseudo-first-order, pseudo-second-order, and intraparticle pore diffusion kinetic models were analyzed. Adsorption isotherms were also analyzed according to the Langmuir and Freundlich models. The obtained results were compared against two commercially activated carbons with comparable surface chemistry and porosimetry. The highest uptake was found for carbons with higher content of basic surface groups. The role of the oxygen-containing groups in the removal of atrazine was estimated experimentally using the surface density. The results were compared with the adsorption energy of atrazine theoretically estimated on pristine and functionalized graphene with different oxygen groups using periodic DFT methods. The energy of adsorption followed the same trend observed experimentally, namely the more basic the pH, the more favored the adsorption of atrazine. Micropores played an important role in the uptake of atrazine at low concentrations, but the presence of mesoporous was also required to inhibit the pore mass diffusion limitations. The present work contributes to the understanding of the interactions between triazine-based pollutants and the surface functional groups on nanoporous carbons in the liquid-solid interface. Adsorption ; Nanoporous ; Atrazine ; Chemistry ; Langmuir ; Freundlich equation ; Chemical engineering ; Diffusion ; Activated carbon ; Mesoporous material ; Organic chemistry ; Catalysis ; Thermodynamics Covalent Organic Framework Applications ; Adsorption and biosorption for pollutant removal ; Environmental remediation with nanomaterials
Authors: Yuichi Yokoyama | Shogo Kawaguchi | Masaichiro Mizumaki
Source: Scientific Reports (article, 2023-09-12)
Field: Materials Science — Materials Chemistry

Bayesian framework for analyzing adsorption processes observed via time-resolved X-ray diffraction Clarifying dynamic processes of materials is an important research topic in materials science. Time-resolved X-ray diffraction is a powerful technique for probing dynamic processes. To understand the dynamics, it is essential to analyze time-series data using appropriate time-evolution models and accurate start times of dynamic processes. However, conventional analyses based on non-linear least-squares fitting have difficulty both evaluating time-evolution models and estimating start times. Here, we establish a Bayesian framework including time-evolution models. We investigate an adsorption process, which is a representative dynamic process, and extract information about the time-evolution model and adsorption start time. The information enables us to estimate adsorption properties such as rate constants more accurately, thus achieving more precise understanding of dynamic adsorption processes. Our framework is highly versatile, can be applied to other dynamic processes such as chemical reactions, and is expected to be utilized in various areas of materials science. Computer science ; Bayesian probability ; Process (computing) ; Adsorption ; Dynamic Bayesian network ; Diffraction ; Biological system ; Bayesian inference ; Time evolution ; Chemistry ; Artificial intelligence ; Physics ; Optics ; Physical chemistry Machine Learning in Materials Science ; X-ray Diffraction in Crystallography ; Crystallography and molecular interactions
Authors: Mackenzie Ridley | Michael J. Lance | Trevor G. Aguirre | Corson L. Cramer
Source: Journal of the American Ceramic Society (article, 2023-09-14)
Field: Materials Science — Ceramics and Composites

Oxidation performance and limitations of additively manufactured SiC/Si─O─C composites at elevated temperatures Abstract SiC preforms were infiltrated with polycarbosiloxane preceramic polymer to create low‐cost SiC—Si x O y C z matrix composites for possible high temperature application. The effect of specimen annealing conditions on the steam and air oxidation resistance was analyzed. Air exposures from 900–1500°C showed stability of the Si x O y C z matrix phase with moderate oxidation resistance. After 900°C exposures, oxidation of the composite is primarily limited to the matrix phase, and only at 1200 and 1500°C was SiC consumption visualized. Steam cycle exposures at 1200°C resulted in rapid linear oxidation of the composites with induced specimen swelling from volume expansion associated with internal oxidation. Specimens annealed in argon were found to be the most oxidation resistant due to increased matrix crystallinity and carbon retention. The results of this work were used to develop clear strategies for improving the high‐temperature properties of SiC—Si x O y C z composites. Materials science ; Composite material ; Crystallinity ; Annealing (glass) ; Composite number ; Swelling ; Argon ; Matrix (chemical analysis) ; Chemistry Advanced ceramic materials synthesis ; Advanced materials and composites ; High-Temperature Coating Behaviors
Authors: Shangzhe Yu | Shidong Zhang | Dominik Schäfer | Roland Peters | Felix Kunz | Rüdiger‐A. Eichel
Source: Preprints.org (preprint, 2023-04-10)
Field: Materials Science — Materials Chemistry

Numerical Modelling and Simulation of the Solid Oxide Cell Stacks and Metal Interconnect Oxidation With OpenFOAM Solid oxide cells are capable of efficiently converting various chemical energy carriers to electricity and vice versa. The urgent challenge nowadays is the faster degradation rate compared with other fuel cell/electrolyzer technologies. To understand the degradation mechanisms, simulation of a solid oxide cell is helpful. Since most previous research developed models using commercial software, such as COMSOL and ANSYS Fluent, a gap for knowledge transfer is being gradually formed between academia and industry due to licensing issues. This paper introduces a multiphysics model, developed by a computational code, openFuelCell2. The code is implemented with an open-source library, OpenFOAM. It accounts for momentum transfer, mass transfer, electrochemical reactions and metal interconnect oxidation. The model can precisely predict I-V curves under different temperatures, fuel humidity and operation modes. Comparison between OpenFOAM and COMSOL simulations shows good agreement. The metal interconnect oxidation is modelled, which can predict the thickness of the oxide scale under different protective coatings. Simulations are conducted by assuming an ultra-thin film resistance on the rib surface. It is revealed that coatings fabricated by atmospheric plasma spraying can efficiently prevent metal interconnect oxidation, with a contribution of only 0.53 \% to the total degradation rate. Multiphysics ; Oxide ; Interconnection ; Materials science ; Solid oxide fuel cell ; Mechanical engineering ; Degradation (telecommunications) ; Fluent ; Electricity ; Mass transfer ; Nuclear engineering ; Computer science ; Nanotechnology ; Process engineering ; Computer simulation ; Simulation ; Mechanics ; Engineering ; Electronic engineering ; Finite element method ; Metallurgy ; Electrical engineering ; Chemistry ; Structural engineering ; Physics Advancements in Solid Oxide Fuel Cells ; Fuel Cells and Related Materials ; Catalytic Processes in Materials Science
Authors: A. Kocot | M. Czarnecka | Yuki Arakawa | Katarzyna Merkel
Source: Molecules (article, 2023-11-06)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Exploring the Impact of Intermolecular Interactions on the Glassy Phase Formation of Twist-Bend Liquid Crystal Dimers: Insights from Dielectric Studies The formation of the nematic to twist-bend nematic (NTB) phase has emerged as a fascinating phenomenon in the field of supramolecular chemistry, based on complex intermolecular interactions. Through a careful analysis of molecular structures and dynamics, we elucidate how these intermolecular interactions drive the complex twist-bend modulation observed in the NTB. The study employs broadband dielectric spectroscopy spanning frequencies from 10 to 2 × 109 Hz to investigate the molecular orientational dynamics within the glass-forming thioether-linked cyanobiphenyl liquid crystal dimers, namely, CBSC7SCB and CBSC7OCB. The experimental findings align with theoretical expectations, revealing the presence of two distinct relaxation processes contributing to the dielectric permittivity of these dimers. The low-frequency relaxation mode is attributed to an “end-over-end rotation” of the dipolar groups parallel to the director. The high-frequency relaxation mode is associated with precessional motions of the dipolar groups about the director. Various models are employed to describe the temperature-dependent behavior of the relaxation times for both modes. Particularly, the critical-like description via the dynamic scaling model seems to give not only quite good numerical fittings, but also provides a consistent physical picture of the orientational dynamics in accordance with findings from infrared (IR) spectroscopy. Here, as the longitudinal correlations of dipoles intensify, the m1 mode experiences a sudden upsurge in enthalpy, while the m2 mode undergoes continuous changes, displaying critical mode coupling behavior. Interestingly, both types of molecular motion exhibit a strong cooperative interplay within the lower temperature range of the NTB phase, evolving in tandem as the material’s temperature approaches the glass transition point. Consequently, both molecular motions converge to determine the glassy dynamics, characterized by a shared glass transition temperature, Tg. Intermolecular force ; Liquid crystal ; Chemical physics ; Relaxation (psychology) ; Molecular dynamics ; Dielectric ; Intramolecular force ; Dipole ; Phase (matter) ; Materials science ; Chemistry ; Supramolecular chemistry ; Condensed matter physics ; Crystallography ; Computational chemistry ; Crystal structure ; Molecule ; Physics ; Stereochemistry ; Organic chemistry Liquid Crystal Research Advancements ; Material Dynamics and Properties ; Nonlinear Dynamics and Pattern Formation
Authors: Zhongqiang Hu | Zhongkui Zhou | Jianping Guo | Yong Liu | Shunjing Yang | Yadan Guo | Liping Wang | Zhanxue Sun | Zhihui Yang
Source: Toxics (article, 2023-03-24)
Field: Chemistry — Inorganic Chemistry

Surface Engineering Design of Nano FeS@Stenotrophomonas sp. by Ultrasonic Chemical Method for Efficient U(VI) and Th(IV) Extraction Nano-FeS has great potential for use in the management of radioactive contaminants. In this paper, we prepared a FeS@<i>Stenotrophomonas</i> sp. composite material by ultrasonic chemistry, and it showed excellent removal of uranium and thorium from the solution. Through optimization of the experimental conditions, it was found that the maximum adsorption capacities for uranium and thorium reached 481.9 and 407.5 mg/g for a composite made with a synthetic ratio of 1:1, pH 5 and 3.5, respectively, for U and Th, and sonication for 20 min. Compared with those of FeS or <i>Stenotrophomonas</i> alone, the removal capacity was greatly improved. The results of a mechanistic study indicated that efficient removal of the uranium and thorium was due to ion exchange, reduction, and microbial surface adsorption. FeS@<i>Stenotrophomonas</i> sp. could be applied to U(VI) and Th(IV) extraction for radioactive water. Uranium ; Thorium ; Adsorption ; Stenotrophomonas ; Extraction (chemistry) ; Sonication ; Chemistry ; Nuclear chemistry ; Central composite design ; Human decontamination ; Response surface methodology ; Materials science ; Chromatography ; Waste management ; Metallurgy ; Organic chemistry Radioactive element chemistry and processing ; Geochemistry and Elemental Analysis ; Chemical Synthesis and Characterization
Authors: Lincoln Satterthwaite | Greta Koumarianou | P. Brandon Carroll | Robert J. Sedlik | Irène Wang | Michael McCarthy | David Patterson
Source: The Journal of Physical Chemistry A (article, 2023-04-29)
Field: Chemistry — Spectroscopy

Low-Temperature Gas-Phase Kinetics of Ethanol–Methanol Heterodimer Formation The structures of gas-phase noncovalently bound clusters have long been studied in supersonic expansions. This method of study, while providing a wealth of information about the nature of noncovalent bonds, precludes observation of the formation of the cluster, as the clusters form just after the orifice of the pulsed valve. Here, we directly observe formation of ethanol-methanol dimers via microwave spectroscopy in a controlled cryogenic environment. Time profiles of the concentration of reagents in the cell yielded gas-phase reaction rate constants of <i>k</i><sub><i>Me</i>-<i>g</i></sub> = (2.8 ± 1.4) × 10<sup>-13</sup> cm<sup>3</sup> molecule<sup>-1</sup> s<sup>-1</sup> and <i>k</i><sub><i>Me</i>-<i>t</i></sub> = (1.6 ± 0.8) × 10<sup>-13</sup> cm<sup>3</sup> molecule<sup>-1</sup> s<sup>-1</sup> for the pseudo-second-order ethanol-methanol dimerization reaction at 8 K. The relaxation cross section between the gauche and trans conformers of ethanol was also measured using the same technique. In addition, thermodynamic relaxation between conformers of ethanol over time allowed for selection of conformer stoichiometry in the ethanol-methanol dimerization reaction, but no change in the ratio of dimer conformers was observed with changing ethanol monomer stoichiometry. Kinetics ; Methanol ; Ethanol ; Gas phase ; Phase (matter) ; Chemistry ; Chemical engineering ; Materials science ; Thermodynamics ; Organic chemistry ; Physics ; Engineering Molecular Spectroscopy and Structure ; Advanced Chemical Physics Studies ; Phase Equilibria and Thermodynamics
Authors: Jan Ulric Garcia | Douglas R. Tree | Alyssa Bagoyo | Tatsuhiro Iwama | Kris T. Delaney | Glenn H. Fredrickson
Source: The Journal of Chemical Physics (article, 2023-12-06)
Field: Materials Science — Materials Chemistry

Coarsening dynamics of ternary polymer solutions with mobility and viscosity contrasts Using phase-field simulations, we investigate the bulk coarsening dynamics of ternary polymer solutions undergoing a glass transition for two models of phase separation: diffusion only and with hydrodynamics. The glass transition is incorporated in both models by imposing mobility and viscosity contrasts between the polymer-rich and polymer-poor phases of the evolving microstructure. For microstructures composed of polymer-poor clusters in a polymer-rich matrix, the mobility and viscosity contrasts significantly hinder coarsening, effectively leading to structural arrest. For microstructures composed of polymer-rich clusters in a polymer-poor matrix, the mobility and viscosity contrasts do not impede domain growth; rather, they change the transient concentration of the polymer-rich phase, altering the shape of the discrete domains. This effect introduces several complexities to the coarsening process, including percolation inversion of the polymer-rich and polymer-poor phases-a phenomenon normally attributed to viscoelastic phase separation. Ternary operation ; Viscosity ; Dynamics (music) ; Polymer ; Thermodynamics ; Materials science ; Statistical physics ; Physics ; Computer science ; Composite material Material Dynamics and Properties ; Rheology and Fluid Dynamics Studies ; Phase Equilibria and Thermodynamics
Authors: Jean Marie Kepdieu | Chantale Njiomou Djangang | Jacques Romain Njimou | Gustave Tchanang | Cyprien Joël Ekani | Sanda Andrada Maicaneanu | Chedly Tizaoui
Source: American Journal of Physical Sciences (article, 2023-10-07)
Field: Chemistry — Organic Chemistry

Theoretical and Experimental Study of the Adsorption of Natural Red 4 Dye from Synthetic Aqueous Media Using a Low-cost Silica-smectite Composite Purpose: A study of the removal of dye Natural red 4 (NR4) by a low-cost silica-smectite clay labeled SSC was carried out. Methodology: Batch tests were carried on with some processing parameters namely initial dye concentration (10 - 50 mg/L), temperature (25 – 65 °C), adsorbent dose (1 – 5 g/L), initial pH (4 – 8) and contact time (0 - 120 min). Findings: The Energy of adsorption was less than 20 kJ/mol showing a physisorption process. Also, thermodynamics parameters such as enthalpy of activation ∆H* (19.0 kJ/mol), entropy of activation ∆S* (- 024 kJ/mol/K) and Gibbs free energy of activation ∆G* (90.57 - 100.17 kJ/mol) revealed that the adsorption of NR4 molecules onto SSC was endothermic and with no significant changes in the internal structure of the adsorbent. The pseudo-first order and pseudo-second order had a good correlation with experimental data with R2 = 0.99 and R2 = 0.98 respectively. Langmuir isotherm model matched well the equilibrium data with a maximum adsorption capacity Qm of 25.55 mg/g. and a correlation value of 0.98. Unique Contribution to Theory, Policy and Practice: The newly synthesized and characterized low-cost silica-smectite composite is effective in the adsorptive removal of natural red 4 dye from water wastes. Adsorption ; Enthalpy ; Gibbs free energy ; Endothermic process ; Chemistry ; Physisorption ; Aqueous solution ; Langmuir adsorption model ; Activation energy ; Thermodynamics ; Nuclear chemistry ; Physical chemistry Synthesis of Tetrazole Derivatives
Authors: Lennart Koch | Burkhard Schmidt
Source: European Journal of Mineralogy (article, 2023-02-27)
Field: Materials Science — Ceramics and Composites

CO<sub>2</sub> diffusion in dry and hydrous leucititic melt Abstract. Using the diffusion couple technique, diffusion of CO2 in a leucititic melt from the Colli Albani Volcanic District in Italy was investigated at temperatures between 1200 and 1350 ∘C in an internally heated pressure vessel at 300 MPa. To examine the effect of dissolved H2O in the melt, experiments were performed for a nominally dry melt (0.18 ± 0.03 wt % H2O) and for a hydrous melt containing 3.36 ± 0.28 wt % H2O. Diffusion experiments were run for 40 to 120 min and terminated by rapid quench. CO2 concentration profiles were subsequently measured via attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and fitted with error functions to obtain individual diffusion coefficients. For the anhydrous and hydrous sample series, seven diffusion coefficients were determined each. Diffusivity was found to increase exponentially with temperature for both melts following an Arrhenius behaviour. The Arrhenius equation for the nominally dry leucititic melt is described by log⁡DCO2=-1.44(±0.24)⋅10000T-1.95(±1.59), where DCO2 is the diffusion coefficient in m2 s−1 and T is the temperature in K. In the experimental temperature range, H2O has an accelerating effect on CO2 diffusion. At 1200 ∘C, diffusivity increases from 1.94 × 10−12 m2 s−1 in the dry melt to 1.54 × 10−11 m2 s−1 in the hydrous melt. The Arrhenius equation for the leucititic melt containing 3.36±0.28 wt % H2O is given by log⁡DCO2=-1.09(±0.30)⋅10000T-3.41(±1.99). The activation energies for CO2 were determined to be 275 ± 47 kJ mol−1 for the anhydrous melt and 209 ± 58 kJ mol−1 for the hydrous melt. The high CO2 activation energy in the leucititic melt indicates that the diffusion might be partly attributed to the carbonate species. At high magmatic temperatures above 1200 ∘C, CO2 diffusivity in the leucititic melt is only slightly lower than CO2 diffusion in rhyolitic and basaltic melts, suggesting that CO2 diffusion in natural melts is relatively independent from the bulk melt composition at such temperatures. CO2 diffuses slower than other volatile components such as halogens and H2O in depolymerized silicate melts. Thus, a fractionation of volatiles can occur during magma ascent and degassing. The experimental data on CO2 diffusion can be used for modelling the degassing mechanisms of ultrapotassic mafic melts. Arrhenius equation ; Diffusion ; Thermal diffusivity ; Analytical Chemistry (journal) ; Anhydrous ; Fourier transform infrared spectroscopy ; Atmospheric temperature range ; Chemistry ; Mineralogy ; Activation energy ; Materials science ; Thermodynamics ; Physical chemistry ; Chromatography ; Chemical engineering ; Organic chemistry Glass properties and applications ; Cultural Heritage Materials Analysis ; Building materials and conservation
Authors: Kun-Chan Lan | Tzu-Hao Tsai | Min‐Chun Hu | Juei-Chun Weng | Junxiang Zhang | Yuan‐Shiun Chang
Source: Evidence-based Complementary and Alternative Medicine (article, 2023-01-01)
Field: Chemistry — Analytical Chemistry

Toward Recognition of Easily Confused TCM Herbs on the Smartphone Using Hierarchical Clustering Convolutional Neural Network Background and Objective . The use of Chinese herbal medicines (CHMs) for treatment plays an important role in traditional Chinese medicine (TCM). However, some herbs are easily confused with the others because their shapes/textures look similar and they could have totally different utilities. Recently, deep learning has attracted great attention for the application of image recognition and could be useful for TCM herb identification. Methods . For recognizing easily‐confused TCM herbs on a smartphone, we propose a CHM recognition system using hierarchical clustering convolutional neural networks (HCNNs) based on the affinity propagation clustering method. Results . We implement our system on the smartphone and show recognition accuracy close to 98%, based on a dataset of 65 kinds of herbs (including 12 easy‐confused herbs pairs). We also investigate the effect of different parameters (e.g., selection of clustering algorithms for HCNNs, types of smartphone, and number of layers in the neural network) on the system performance. Conclusions . In this work, we proposed a hierarchical clustering convolutional neural network (HCNN) method to distinguish similar TCM herbs with a high accuracy. We also showed the usefulness of applying the data augmentation techniques when implementing the proposed system for a variety of smartphones. Convolutional neural network ; Cluster analysis ; Computer science ; Hierarchical clustering ; Artificial intelligence ; Pattern recognition (psychology) Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Metabolomics and Mass Spectrometry Studies