jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zilong Hua | Saqeeb Adnan | Amey Khanolkar | Karl Rickert | David B. Turner | Timothy A. Prusnick | J. Matthew Mann | David H. Hurley | Marat Khafizov | Cody A. Dennett
Source: Journal of Materiomics (article, 2023-12-05)
Field: Materials Science — Materials Chemistry

Thermal conductivity suppression in uranium-doped thorium dioxide due to phonon-spin interactions In this work, impact of low level of uranium (U) atom substitution on thermal conductivity of thorium dioxide (ThO2) is investigated. ThO2 is an electronic insulator with a wide optical band-gap and no unpaired electrons whose thermal transport is governed by phonons. U-substitution introduces unpaired f-electrons resulting in paramagnetic behavior of UThO2 at room temperature, which significantly suppresses its thermal conductivity. A single crystal of UThO2 with graded composition of U is grown using a hydrothermal synthesis method, and thermal conductivity measurements are performed in regions with uniform composition of U at levels of 0 %, 6 %, 9 % and 16 %. Measured thermal conductivity profiles over 77–300 K temperature range are analyzed using an analytical expression for phonon-mediated thermal transport based on Klemens-Callaway model. Temperature dependent thermal conductivity is found to deviate significantly from the Rayleigh scattering trend expected for a simple substitutional point defect with a small perturbation to mass and interatomic forces. With the resonant scattering term, observed large suppression of thermal conductivity at low temperatures can be closely reproduced. Additionally, the extracted phonon-spin coupling constants imply a nonlinear relation of phonon-spin interaction intensity with respect to U doping percentage. Our study reveals how phonon-spin scattering contributed by unpaired f-electrons in U atoms influences thermal transport in the UThO2 system. Thermal conductivity ; Condensed matter physics ; Materials science ; Phonon ; Phonon scattering ; Electron ; Physics Nuclear Materials and Properties ; Thermal Expansion and Ionic Conductivity ; Advanced Thermoelectric Materials and Devices
Authors: Katherine Montoya | Brian A. Brigham | Grant Helmreich | Jesse Werden | Tyler Gerczak | Elizabeth S. Sooby
Source: Journal of Nuclear Materials (article, 2023-03-12)
Field: Materials Science — Ceramics and Composites

Microstructural analysis of tristructural isotropic particles in high-temperature steam mixed gas atmospheres Materials science ; Layer (electronics) ; Scanning electron microscope ; Atmosphere (unit) ; Chemical engineering ; Isotropy ; Composite material ; Thermodynamics Advanced ceramic materials synthesis ; Nuclear Materials and Properties ; Nuclear materials and radiation effects
Authors: P. Mogilevsky | Michael K. Cinibulk
Source: Journal of the American Ceramic Society (article, 2023-09-22)
Field: Materials Science — Ceramics and Composites

Oxidation kinetics of silicon carbide‐containing refractory diborides, I: Revised model Abstract The original model by Parthasarathy et al. for oxidation of MeB₂–SiC ultra‐high temperature ceramics (UHTCs) has been further expanded to include oxidation by water vapor and oxygen/water vapor mixtures. The revised model offers a more representative analysis of the composition of the glass phase and a thermodynamically consistent formulation for the processes governing the formation of the internal depletion zone. A key feature of the revised model is that it explicitly incorporates the out‐diffusion of CO(g) through the scale as a rate‐controlling parameter that defines the formation of internal depletion zone. In its present form, the expanded model explains some of the experimentally observed phenomena of oxidation of MeB₂–SiC UHTCs, such as the formation of MeO₂/B₂O₃ scale with embedded partially oxidized SiC at lower temperatures and limited growth of ZrO₂/borosilicate layer compared with the SiC‐depleted layer and the outer borosilicate layer in static oxidation at high temperatures. Application of the revised model to the experimental data from literature on oxidation of ZrB₂–SiC materials in air and water vapor is demonstrated and discussed. Borosilicate glass ; Silicon carbide ; Internal oxidation ; Materials science ; Water vapor ; Ceramic ; Kinetics ; Diffusion ; Layer (electronics) ; Oxide ; Carbide ; Chemical engineering ; Silicon ; Thermodynamics ; Mineralogy ; Composite material ; Metallurgy ; Chemistry Advanced ceramic materials synthesis ; Advanced materials and composites ; MXene and MAX Phase Materials
Authors: K. Cavé | Damien Texier | Sylvain Vallot | Nicolas Chanfreau | E. Fessler | Moukrane Dehmas | Daniel Monceau | Dominique Poquillon
Source: Scripta Materialia (article, 2023-09-04)
Field: Materials Science — Materials Chemistry

Effect of creep loading on the oxygen diffusion of Ti6242S at 650°C Materials science ; Oxygen ; Electron microprobe ; Diffusion ; Oxide ; Creep ; Analytical Chemistry (journal) ; Limiting oxygen concentration ; Secondary ion mass spectrometry ; Synchrotron ; Oxygen transport ; Metallurgy ; Mass spectrometry ; Thermodynamics ; Chemistry Nuclear Materials and Properties ; Titanium Alloys Microstructure and Properties ; Intermetallics and Advanced Alloy Properties
Authors: C. Singer | Harald Behrens | I. Horn | Martin Oeser | Ralf Dohmen | Stefan Weyer
Source: European Journal of Mineralogy (article, 2023-11-16)
Field: Materials Science — Ceramics and Composites

Li–Na interdiffusion and diffusion-driven lithium isotope fractionation in pegmatitic melts Abstract. In this study, we investigate the diffusion of Li and its stable isotopes (6Li and 7Li) in flux-rich (1.8 % Li2O, 2.6 % B2O3, 2.3 % P2O5 and 3 % F) pegmatitic melts in order to contribute to the understanding of Li enrichment in such systems. Two glasses were synthesized with a model pegmatitic composition, one of which is highly enriched in Li (&gt; 1 wt %, PEG2-blue) and the other one essentially Li-free (PEG2-Li-free). Diffusion couple experiments were performed to determine the chemical diffusivity of Li in dry pegmatitic melts. Experiments were conducted using rapid-heat and rapid-quench cold-seal pressure vessels in a temperature range of 650–940 ∘C at 100 MPa with Ar as the pressure medium. We observed rapidly formed diffusion profiles, driven by an interdiffusive exchange of the monovalent alkalis Li and Na, while the other elements are immobile on the timescale of experiments (1–30 min). From these experiments, activation energies for Li–Na interdiffusion were determined as 99 ± 7 kJ mol−1 with a pre-exponential factor of log D0 = −5.05 ± 0.33 (D0 in m2 s−1). Li and Na partitioning between the stronger depolymerized PEG2-blue and the less depolymerized PEG2-Li-free leads to a concentration jump at the interface; i.e. Na is enriched in the more depolymerized PEG2-blue. Li–Na interdiffusion coefficients in the studied melt composition are in a similar range as Li and Na tracer diffusivities in other dry aluminosilicate melts, confirming little to no effect of aluminosilicate melt composition on Li diffusivity. Thus, added fluxes do not enhance the Li diffusivity in the same way as observed for H2O (Holycross et al., 2018; Spallanzani et al., 2022). Using melt viscosity as a proxy for the polymerization of the melt shows that water has a stronger potential to depolymerize a melt compared to other fluxing elements. Faster diffusion of 6Li compared to 7Li leads to a strong Li isotope fractionation along the diffusion profile, resulting in δ7Li as low as −80 ‰ relative to the diffusion-unaffected regions. This diffusive isotope fractionation can be quantified with an empirical isotope fractionation factor (β) of 0.20 ± 0.04, similar to previously observed β values for Li diffusion in melts. This suggests in accordance with previously published data that a β value of ca. 0.2 seems to be universally applicable to diffusive Li isotope fractionation in aluminosilicate melts. Chemistry ; Diffusion ; Lithium (medication) ; Analytical Chemistry (journal) ; Aluminosilicate ; Thermal diffusivity ; Fractionation ; Atmospheric temperature range ; Mineralogy ; Chromatography ; Thermodynamics ; Organic chemistry Glass properties and applications ; Nuclear materials and radiation effects ; Geological and Geochemical Analysis
Authors: Milton Assunção | M. Vynnycky
Source: European Journal of Applied Mathematics (article, 2023-03-23)
Field: Materials Science — Materials Chemistry

On macrosegregation in a binary alloy undergoing solidification shrinkage Abstract The one-dimensional transient solidification of a binary alloy undergoing shrinkage is well-known as an invaluable benchmark for the testing of numerical codes that model macrosegregation. Here, recent work that considered the small-time behaviour of this problem is extended until complete solidification, thereby determining the solute profile across the entire solidified domain. The small-time solution is used as the initial condition for the numerical integration of a problem having three moving boundaries. Of particular significance is the so-called inverse segregation that is observed at the start of solidification, and the extreme segregation that is observed at the end; in the case of the example presented, which is for the often-cited Al–Cu system, the macrosegregation is found to be positive or negative, depending on whether Scheil’s equation or the lever rule is assumed at the microscale, respectively. The relevance of these results for the modelling of steady-state continuous casting processes – in particular, the phenomenon of centreline segregation – is also discussed. Microscale chemistry ; Shrinkage ; Materials science ; Binary alloy ; Transient (computer programming) ; Benchmark (surveying) ; Casting ; Mechanics ; Work (physics) ; Binary number ; Alloy ; Thermodynamics ; Metallurgy ; Computer science ; Mathematics ; Physics ; Composite material ; Geology Solidification and crystal growth phenomena ; Aluminum Alloy Microstructure Properties ; nanoparticles nucleation surface interactions
Authors: Mithlesh Yadav | Balasubramanian Narasimhan | Archana Kapoor
Source: Current Chemistry Letters (article, 2023-10-06)
Field: Chemistry — Organic Chemistry

Development of 2-dimensional and 3-dimensional QSAR models of Indazole derivatives as TTK inhibitors having Anticancer potential The study aimed to explore the anticancer efficacy of indazole pharmacophore by analyzing a series of 109 derivatives of indazole as Tyrosine Threonine Kinase (TTK) inhibitors through quantitative activity relationship analysis using 2D and 3D QSAR techniques. The best 2D-QSAR model was generated by the MLR method, showing a high correlation coefficient (r2) of 0.9512, and good internal (q2), and external (pred_r2) cross-validation regression coefficients of 0.8998, and 0.8661, respectively. The residual values were modest, indicating good agreement between the observed and predicted pIC50 values, which suggested that the chosen model was predictably accurate. The 3D QSAR model, built using the SWF kNN approach, displayed a high internal cross-validation regression coefficient (q2) of 0.9132. Essential structural features/considerations in developing indazole as prospective anticancer medicines have been suggested. The study provides a reliable and predictive model for the prediction of anticancer activity of indazole derivatives. The identified essential structural features/considerations may be useful for the development of prospective anticancer medicines. Indazole ; Quantitative structure–activity relationship ; Chemistry ; Pharmacophore ; Correlation coefficient ; Stereochemistry ; Combinatorial chemistry ; Machine learning ; Computer science Synthesis and biological activity ; Computational Drug Discovery Methods ; Click Chemistry and Applications
Authors: Andreea Veronica Dediu Botezatu | Gabriela Bahrim | Claudia Veronica Ungureanu | Anna Cazanevscaia Busuioc | Bianca Furdui | Rodica Mihaela Dinică
Source: Green Processing and Synthesis (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

Green “one-pot” fluorescent bis-indolizine synthesis with whole-cell plant biocatalysis Abstract An efficient one-pot route leading to bis-indolizine symmetric compounds has been developed via a new approach from the dipyridinium heterocyclic compound, reactive halogenated derivative, and activated alkyne through biocatalysis. A set of local plants was evaluated for its catalytic potential in “one-pot” biocatalysis of these valuable fluorescent compound synthesis reactions. Most of these biocatalysts containing enzymes from the oxidoreductase class (peroxidase: 0.56–1.08 mmol purpurogallin‧g −1 fresh weight‧min −1 , polyphenol oxidase (PPO) : 27.19–48.95 PPO units‧mg tissue −1 , CAT: 3.27–21.71 µmol O 2 ‧g −1 fresh weight‧min −1 ), were used as green catalysts in the multi-component cycloaddition reaction, in an aqueous buffer solution, for the production of bis-indolizine compounds in moderate to excellent yields (45–85%). The horseradish root ( Armoracia rusticana ) has been selected as the most promising biocatalyst source among the evaluated plants, and the obtained yields were greater than in the conventional synthesis method. The structures of indolizine derivatives were confirmed by nuclear magnetic resonance spectra, elemental analyses, as well as Fourier transform-infrared spectra. The cytotoxicity of the latter obtained indolizine compounds on the growth of the model microorganism, Saccharomyces cerevisiae MIUG 3.6 yeast strain, was also evaluated. Various parameters (number of generations, growth rate, generation time, dry matter yield, the degree of the budding yeast cells, and the degree of yeast autolysis, fermentation intensity), which describe the yeast growth, suggest that the nutrient broth supplemented with different concentrations of bis-indolizine compounds (10 and 1 µM) had no toxic effect on the yeast strain growth, under submerged cultivation conditions. Indolizine ; Biocatalysis ; Chemistry ; Yeast ; Catalysis ; Organic chemistry ; Reaction mechanism ; Biochemistry Synthesis and Reactivity of Heterocycles ; Cyclopropane Reaction Mechanisms ; Synthesis and Characterization of Pyrroles
Authors: Mattia Bartoli | Elena Marras | Alberto Tagliaferro
Source: Molecules (article, 2023-06-09)
Field: Materials Science — Materials Chemistry

Computational Investigation of Interactions between Carbon Nitride Dots and Doxorubicin The study of carbon dots is one of the frontiers of materials science due to their great structural and chemical complexity. These issues have slowed down the production of solid models that are able to describe the chemical and physical features of carbon dots. Recently, several studies have started to resolve this challenge by producing the first structural-based interpretation of several kinds of carbon dots, such as graphene and polymeric ones. Furthermore, carbon nitride dot models established their structures as being formed by heptazine and oxidized graphene layers. These advancements allowed us to study their interaction with key bioactive molecules, producing the first computational studies on this matter. In this work, we modelled the structures of carbon nitride dots and their interaction with an anticancer molecule (Doxorubicin) using semi-empirical methods, evaluating both geometrical and energetic parameters. Graphene ; Nanotechnology ; Carbon fibers ; Materials science ; Carbon nitride ; Quantum dot ; Molecule ; Chemistry ; Organic chemistry ; Composite material Carbon and Quantum Dots Applications ; Graphene and Nanomaterials Applications ; Boron and Carbon Nanomaterials Research
Authors: Orkid Coskuner‐Weber | Elif Yüce | Vladimir N. Uversky
Source: Polymers (review, 2023-02-02)
Field: Materials Science — Biomaterials

Paving the Way for Synthetic Intrinsically Disordered Polymers for Soft Robotics Nature is full of examples of processes that, through evolution, have been perfected over the ages to effectively use matter and sustain life. Here, we present our strategies for designing intrinsically disordered smart polymers for soft robotics applications that are bio-inspired by intrinsically disordered proteins. Bio-inspired intrinsically disordered smart and soft polymers designed using our deep understanding of intrinsically disordered proteins have the potential to open new avenues in soft robotics. Together with other desirable traits, such as robustness, dynamic self-organization, and self-healing abilities, these systems possess ideal characteristics that human-made formations strive for but often fail to achieve. Our main aim is to develop materials for soft robotics applications bio-inspired by intrinsically disordered proteins to address what we see as the largest current barriers in the practical deployment of future soft robotics in various areas, including defense. Much of the current literature has focused on the de novo synthesis of tailor-made polymers to perform specific functions. With bio-inspired polymers, the complexity of protein folding mechanisms has limited the ability of researchers to reliably engineer specific structures. Unlike existing studies, our work is focused on utilizing the high flexibility of intrinsically disordered proteins and their self-organization characteristics using synthetic quasi-foldamers. Soft robotics ; Soft materials ; Intrinsically disordered proteins ; Artificial intelligence ; Robotics ; Flexibility (engineering) ; Nanotechnology ; Computer science ; Soft matter ; Evolutionary robotics ; Folding (DSP implementation) ; Human–computer interaction ; Materials science ; Robot ; Engineering ; Biology ; Mechanical engineering ; Mathematics ; Biophysics Supramolecular Self-Assembly in Materials ; Advanced Materials and Mechanics ; Chemical Synthesis and Analysis
Authors: Chonthicha Kongkwamcharoen | Arunporn Itharat | Wichan Ketjinda | Hyang‐Yeol Lee | Gi‐Seong Moon | Neal M. Davies
Source: Research in Pharmaceutical Sciences (article, 2023-03-11)
Field: Chemistry — Organic Chemistry

Formulation design and physicochemical evaluation of an anti-inflammatory hydrogel patch containing Crinum asiaticum L. extract The optimized CAE hydrogel patch application was successfully formulated with excellent mechanical properties, cumulative release, permeation, and anti-inflammatory effects. Thus, it has the potential to be further developed as a herbal application to relieve pain and inflammation. The <i>in vivo</i> anti-inflammatory effect of this delivery system should be further investigated. Locust bean gum ; Ultimate tensile strength ; Permeation ; Chemistry ; Carrageenan ; Box–Behnken design ; In vivo ; Anti-inflammatory ; Plasticizer ; Response surface methodology ; In vitro ; Pharmacology ; Traditional medicine ; Chromatography ; Materials science ; Food science ; Medicine ; Composite material ; Biochemistry ; Organic chemistry ; Biotechnology ; Biology Chemical synthesis and alkaloids ; Botanical Research and Applications ; Fungal Biology and Applications
Authors: Ömer Faruk Altundal | Germán Sastre
Source: The Journal of Physical Chemistry C (article, 2023-07-31)
Field: Chemistry — Inorganic Chemistry

The Directing Role of Aluminum in the Synthesis of PST-21 (PWO), PST-22 (PWW), and ERS-7 (ESV) Zeolites Zeolites are a diverse class of crystalline microporous materials of, mainly, aluminosilicate chemical composition. Organic structure-directing agents (OSDAs) are generally utilized in zeolite synthesis to drive the outcome to a specific zeolite phase. In addition to OSDA, the presence and content of aluminum in the gel play a role in driving the synthesis under specific conditions. The structure-directing role of aluminum as well as fluoride in zeolite synthesis was explored through the analysis of three recently synthesized aluminosilicate zeolites, PST-21 (PWO), PST-22 (PWW), and ERS-7 (ESV), using a force field simulation approach. An updated and recently proposed method based on the calculation of “synthesis energy” is used to predict the stability of zeolites at pure-silica and aluminosilicate gel compositions, also able to include fluoride anions as well as OSDAs, and hence largely general. The results are not only demonstrating that the calculated structures with lowest “synthesis energy” correspond to those experimentally obtained under “standard” (meaning HF/SDA = 1) synthesis conditions but also that new structures obtained under the recently introduced “excess fluoride approach” are those which follow with energy slightly larger than the lowest, as calculated from the list of competing zeolites. With this method, we were able to rationalize the structure-directing effect of aluminum, in the presence of fluoride and OSDAs, in the synthesis of zeolites. Aluminosilicate ; Zeolite ; Microporous material ; Fluoride ; Aluminium ; Materials science ; Chemical engineering ; Inorganic chemistry ; Chemistry ; Catalysis ; Organic chemistry ; Composite material Zeolite Catalysis and Synthesis ; Chemical Synthesis and Characterization ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Abd El‐Aziz A. Said | Aya Ali Shaban | Mohamed N. Goda
Source: Catalysis Letters (article, 2023-06-02)
Field: Materials Science — Materials Chemistry

Zirconia Incorporated Aluminum Phosphate Molecular Sieves as Efficient Microporous Nano Catalysts for the Selective Dehydration of Methanol into Dimethyl Ether Abstract Annually, a growing demand was noted for replacing petroleum fuels with second-generation eco-friendly fuels like dimethyl ether (DME). Methanol dehydration into DME process has been considered as one of the potential pathways for the manufacture of a clean fuel. However, stable, and active catalyst is exceedingly requisite for generation of DME particularly at reasonably low temperature. In the current study, zirconia incorporated AlPO 4 tridymite microporous molecular sieve catalysts were fabricated by a hydrothermal method in the presence of triethylamine (TEA) as a structure directing agent. The catalysts were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and N 2 -sorption assessments. Catalysts’ acidity was estimated by decomposition of isopropanol, pyridine and dimethyl pyridine chemisorption, and pyridine-TPD. Results revealed that catalysts surfaces composed acid sites of Brønsted nature and of weak and medium strengths. Activity results showed that 1 wt% H 2 SO 4 modified zirconia incorporated AlPO 4 -TRI catalyst calcined at 400 °C presented the best activity with a conversion of 89% and a 100% selectivity into DME at 250 °C. The significant catalytic activity is well-connected to the variation in BET-surface area, acidity, and activation energy of methanol dehydration. The catalysts offered long-term stability for 120 h and could be regenerated with almost the same activity and selectivity. Graphical Abstract Chemistry ; Catalysis ; Dimethyl ether ; Methanol ; Thermogravimetric analysis ; Microporous material ; Inorganic chemistry ; BET theory ; Nuclear chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Zeolite Catalysis and Synthesis ; Catalysis and Hydrodesulfurization Studies