jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Kongtan Yang | Xumi Wang | Huanqi Wu | Nan Fang | Yuxue Liu | Changpeng Zhang | Xiaobin Yu | Xiangyun Wang
Source: Sustainability (article, 2023-10-08)
Field: Chemistry — Analytical Chemistry

Adsorption of Pyraclostrobin in Water by Bamboo-Derived and Pecan Shell-Derived Biochars Pyraclostrobin is a potent extensive-spectrum fungicide widely used in agricultural production but poses a substantial threat to aquatic life. Therefore, there is an urgent need to remove pyraclostrobin from the ecological environment. This study reports the adsorption of pyraclostrobin in water using pecan-shell biochar, bamboo biochar, and their deashing products. The kinetics and isotherms indicate that the pseudo-second-order kinetics and Freundlich model are the most suitable for both types of biochar. The thermodynamic results demonstrate that the adsorption process of biochar is spontaneous and exothermic. Combined with characterization and factor analysis experiments, it is revealed that the adsorption of pyraclostrobin on biochar is attributed to various mechanisms, including pore filling, hydrophobic interactions, π-π and p-π interactions, and hydrogen bonding. At the initial concentration of 0.5 mg·L−1, the adsorption rates of pyraclostrobin of the four biochar samples (&lt;0.075 mm) reached 67–80% within 5 min. These findings suggest that both pecan-shell and bamboo biochars are efficient pyraclostrobin adsorbents, with the former showing better outcomes. There is still an adsorption rate of &gt;97% after 5 cycles of adsorption by two types of biochars. Deashing significantly enhances the adsorption efficiency of pecan biochar, but it has an insignificant effect on bamboo biochar. This study will aid in the selection of cost-effective and ecofriendly adsorbents to reduce the environmental risk associated with pyraclostrobin. Biochar ; Adsorption ; Bamboo ; Chemistry ; Exothermic reaction ; Environmental chemistry ; Exothermic process ; Pulp and paper industry ; Materials science ; Pyrolysis ; Organic chemistry ; Composite material Analytical chemistry methods development ; Pharmaceutical and Antibiotic Environmental Impacts ; Pesticide and Herbicide Environmental Studies
Authors: Daniela Mojica | Mauricio Angeles | Óscar Álvarez | Diego Pradilla
Source: Colloids and Interfaces (article, 2023-01-10)
Field: Chemistry — Analytical Chemistry

Asphaltene Precipitation and the Influence of Dispersants and Inhibitors on Morphology Probed by AFM Bridging the gap between laboratory-scale experiments and actual oilfield operations is a complex task that requires a compromise between real (authentic) fluids and model systems. Commercial products (i.e., asphaltene inhibitors and dispersants) are often designed to target a wide range of operating conditions and compositions of crude oils, which means that the performance becomes almost case-specific. Through Atomic Force Microscopy (AFM) imaging and Transmission/Backscattering signals (T/BS), the morphology of asphaltene deposits and the mechanisms that eventually lead to precipitated material were evaluated. Two different models (starting solutions) with four different n-alkanes were used to induce variability in asphaltene agglomeration and subsequent precipitation paths. It was found that increasing the carbon number shifted the observed precipitation detection time (T/BS data suggested a shift in the order of ~1000 s when comparing low and high carbon numbers) and influences the density of the precipitated material under static and a sufficiently high concentration of solvent conditions. Further analysis on the morphology of the resulting material after the addition of commonly used chemicals showed that asphaltene stability through inhibition (i.e., blockage or crowding of potential active sites) led to smaller complexes. One of the additives (PIBSA) reduced the average height in ~33% and the mean square roughness in ~72%. On the other hand, stability through dispersion (i.e., hindering agglomeration) leads to a polymer-like network bigger in size, noting that in both cases the system remains soluble. The use of APR resulted in an increase of ~41% and ~54% for the same parameters. This insight sheds light on how to devise efficient chemical strategies to prevent flow assurance issues. Asphaltene ; Dispersant ; Economies of agglomeration ; Precipitation ; Chemical engineering ; Dispersion (optics) ; Materials science ; Polymer ; Flocculation ; Morphology (biology) ; Atomic force microscopy ; Chemistry ; Nanotechnology ; Mineralogy ; Composite material ; Organic chemistry ; Geology ; Optics ; Meteorology Petroleum Processing and Analysis ; Hydrocarbon exploration and reservoir analysis ; Enhanced Oil Recovery Techniques
Authors: Shuo Yang | Yong Wang | P.P. Man
Source: Fire (article, 2023-10-20)
Field: Materials Science — Polymers and Plastics

Kinetic Analysis of Thermal Decomposition of Polyvinyl Chloride at Various Oxygen Concentrations PVC plastic products are common combustible substances seen in fires, but their thermal degradation behavior under different oxygen concentrations has not been adequately studied. The thermal degradation behavior of PVC materials in atmospheres with different oxygen concentrations was analyzed via thermogravimetric–Fourier transform infrared spectroscopy (TG-FTIR). The TG results show that the thermal degradation process of PVC under a non-oxygenated atmosphere occurred in two stages, and the activation energies of the two stages were 130–175 KJ mol−1 and 230–320 KJ mol−1, respectively; under the oxygenated atmosphere, the thermal degradation process occurred in three stages. The activation energies of the three stages were 130–175 KJ mol−1, 145–510 KJ mol−1 and 75–190 KJ mol−1, respectively. And the reaction mechanism of the second stage of thermal degradation was changed from D-ZLT3 to En by the higher oxygen concentration. Infrared spectroscopy (FTIR) was used to analyze the pyrolysis process of PVC in the non-oxygenated atmosphere, and the eight major components were as follows, in descending order according to amount released: C-H stretching &gt; HCl &gt; C-Cl stretching &gt; H2O &gt; CO2 &gt; C-H bending &gt; C-H aliphatic bending &gt; CH2. For the reaction of PVC at an oxygen concentration of 7%, the nine major components, in descending order according to amount released, were as follows: CO2 &gt; HCl &gt; H2O &gt; CO &gt; C-H stretching &gt; C-Cl stretching &gt; C-H aliphatic bending &gt; C-H bending &gt; CH2. For PVC reactions at oxygen concentrations of 14% and 21%, the five major components, in descending order according to amount released, were CO2 &gt; HCl &gt; CO &gt; C-Cl stretching &gt; H2O. Thermogravimetric analysis ; Oxygen ; Fourier transform infrared spectroscopy ; Thermal decomposition ; Infrared spectroscopy ; Degradation (telecommunications) ; Chemistry ; Thermal analysis ; Pyrolysis ; Activation energy ; Decomposition ; Order of reaction ; Nuclear chemistry ; Kinetics ; Analytical Chemistry (journal) ; Thermal ; Chemical engineering ; Organic chemistry ; Reaction rate constant Polymer Science and PVC ; Polymer crystallization and properties ; Polymer Nanocomposites and Properties
Authors: Niklas Hansson | Mats Jönsson | Christian Ekberg | Kastriot Spahiu
Source: Journal of Nuclear Materials (article, 2023-03-01)
Field: Chemistry — Inorganic Chemistry

Modelling radiation-induced oxidative dissolution of UO2-based spent nuclear fuel on the basis of the hydroxyl radical mediated surface mechanism A combined kinetic and diffusion model with an accurate α-dose rate profile was used to model radiation induced dissolution of UO2. Previous experimental data were used to fit the surface site reaction system involving the surface bound hydroxyl radical as an intermediate species for both UO2 oxidation and surface catalysed decomposition of H2O2. The performance of the model was explored in terms of sensitivity to spatial and temporal resolution as well as simplifications in the models describing the surface reactions and the reactions in solution. As a result, optimal conditions for running the numerical simulations were identified. Dissolution ; Hydroxyl radical ; Decomposition ; Chemistry ; Reaction mechanism ; Diffusion ; Surface (topology) ; Kinetics ; Radiation ; Radical ; Photochemistry ; Thermodynamics ; Physical chemistry ; Catalysis ; Organic chemistry ; Geometry ; Physics ; Nuclear physics ; Mathematics Radioactive element chemistry and processing ; Nuclear Materials and Properties ; Catalytic Processes in Materials Science
Authors: Aleksey Kudreyko | Vladimir G. Chigrinov | Gurumurthy Hegde | Д. Н. Чаусов
Source: Crystals (article, 2023-06-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Photoaligned Liquid Crystalline Structures for Photonic Applications With the advancement of information display technologies, research on liquid crystals is undergoing a tremendous shift to photonic devices. For example, devices and configurations based on liquid crystal materials are being developed for various applications, such as spectroscopy, imaging, and fiber optics. One of the problems behind the development of photonic devices lies in the preparation of patterned surfaces that can provide high resolution. Among all liquid crystal alignment techniques, photoalignment represents a promising non-contact method for the fabrication of patterned surfaces. In this review, we discuss the original research findings on electro-optic effects, which were mainly achieved at the Department of Electronic and Computer Engineering of the Hong Kong University of Science and Technology and the collaborating research laboratories. Photonics ; Materials science ; Liquid crystal ; Fabrication ; Nanotechnology ; Photonic crystal ; High resolution ; Optoelectronics ; Engineering physics ; Optics ; Computer science ; Engineering ; Physics Liquid Crystal Research Advancements ; Photonic Crystals and Applications ; Semiconductor Lasers and Optical Devices
Authors: Merlin Simo Tagne | André Zoulalian | Donatien Njomo | Beguidé Bonoma
Source: Journal of Renewable Energies (article, 2023-10-24)
Field: Materials Science — Polymers and Plastics

Modelisation of desorption isotherms and estimation of the thermophysic and thermodynamic properties of tropical woods in Cameroon: The case of Ayous and Ebony woods A review at various models illustrates the necessary of choosing a model that can best describe each wood in relation to its isotherms of desorption. The theoretical models enable us to deduce several thermo physical parameters. The models of Dent and G.A.B are quite appropriate in the evaluation of the isotherms of desorption of Ayous and Ebony woods taking the humidity of the atmosphere air into consideration. The parameters of Dent’s model vary favourably with regard to the theoretical precisions. The level of humidity at fiber saturation points are at 0.2944 for Ayous wood and 0.19141 for Ebony wood. The specific surface area occupied by the woods under study decreases when there is a consequent increase in temperature. The specific surface area of Ayous wood ranges between 295 and 162 m2/g whereas that of Ebony ranges between 183 and 96 m2/g, while the wood temperatures vary between 20 and 60°C. It is realised that, there is a powerful relationship existing between the primary hydrophiles of Ebony and the first layer of mater molecules. The desorption heat of multi layers of our woods are superior to latent heat condensation of pure water. The heat condensation of water vapour constitutes a specific given which is superior to the heat isosteric adsorption of the woods in question. The soret effect is more important in the drying of Ayous wood than that of Ebony. However, temperature does not influence the soret effect for Ebony wood, relative air humidity is less than 0.85. This limits Ayous wood at 0.9. Above these limits soret effect increases when there is an increase in atmospheric air temperature. Desorption ; Humidity ; Adsorption ; Condensation ; Water vapor ; Relative humidity ; Saturation (graph theory) ; Thermodynamics ; Latent heat ; Chemistry ; Environmental science ; Materials science ; Mathematics ; Organic chemistry ; Physics Textile materials and evaluations ; Wood Treatment and Properties ; Natural Fiber Reinforced Composites
Authors: Philippe F. Weck | Eunja Kim
Source: Chemical Physics Letters (article, 2023-12-17)
Field: Materials Science — Metals and Alloys

High-temperature chromium diffusion in austenitic stainless steel: Ab initio molecular dynamics simulations Grain boundary ; Molecular dynamics ; Chromium ; Diffusion ; Materials science ; Ab initio ; Grain boundary diffusion coefficient ; Austenite ; Corrosion ; Austenitic stainless steel ; Thermodynamics ; Ab initio quantum chemistry methods ; Physical chemistry ; Chemical physics ; Metallurgy ; Computational chemistry ; Microstructure ; Chemistry ; Molecule ; Physics Hydrogen embrittlement and corrosion behaviors in metals ; Fusion materials and technologies ; High-Temperature Coating Behaviors
Authors: A. S. Saleh | Kristof Croes | H. Ceric | Ingrid De Wolf | Houman Zahedmanesh
Source: Journal of Applied Physics (article, 2023-10-02)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A framework for combined simulations of electromigration induced stress evolution, void nucleation, and its dynamics: Application to nano-interconnect reliability A comprehensive physics-based modeling framework for electromigration (EM) in copper nano-interconnects is presented. It combines the three stages of stress evolution, void nucleation, and void dynamics in a single fully coupled and consolidated platform. Mechanical stress evolution, pre- and post-void nucleation, and its impact on void dynamics are deciphered, which enables accurate predictions of EM aging processes as validated by dedicated EM experiments. Subsequently, the experimentally validated model is utilized to shed light on the impact of a number of manufacturing variables, namely, line extension, via taper angle, and the effectiveness of the via bottom flux divergence point. A linear correlation between the ion leakage through the via bottom barrier and the peak tensile stress at the cathode was observed in long lines. In short lines, a blocked cathode end with atomic leakage through the anode end weakens the back-stress effect and threatens the Blech effect induced interconnect immortality. Increasing the line extension length was shown to increase the EM lifetime by about 40%. This impact was saturated beyond 1 critical dimension of line extension. On the other hand, the via taper angle increased the upstream EM lifetime by about twofold when the taper angle was increased from 0° to 30°, which indicates that the change of via taper angle has a stronger impact on EM lifetime compared to the line extension. Electromigration ; Materials science ; Void (composites) ; Nucleation ; Cathode ; Interconnection ; Ultimate tensile strength ; Nano- ; Leakage (economics) ; Anode ; Mechanics ; Composite material ; Chemistry ; Physics ; Thermodynamics ; Electrode ; Computer science ; Engineering ; Electrical engineering Copper Interconnects and Reliability ; Semiconductor materials and devices ; Metal and Thin Film Mechanics
Authors: Seong Won Lee | Woo Hun Choi | HyunHee Cho | Sanghun Lee | Wookyoung Choi | Jinsoo Joo | Donghun Lee | Su‐Hyun Gong
Source: Nano Letters (article, 2023-05-11)
Field: Materials Science — Materials Chemistry

Electric-Field-Driven Trion Drift and Funneling in MoSe<sub>2</sub> Monolayer Excitons, electron-hole pairs in semiconductors, can be utilized as information carriers with a spin or valley degree of freedom. However, manipulation of excitons' motion is challenging because of their charge-neutral characteristic and short recombination lifetimes. Here we demonstrate electric-field-driven drift and funneling of charged excitons (i.e., trions) toward the center of a MoSe<sub>2</sub> monolayer. Using a simple bottom-gate device, we control the electric fields in the vicinity of the suspended monolayer, which increases the trion density and pulls down the layer. We observe that locally excited trions are subjected to electric force and, consequently, drift toward the center of the stretched layer. The exerting electric force on the trion is estimated to be 10<sup>2</sup>-10<sup>4</sup> times stronger than the strain-induced force in the stretched monolayer, leading to the successful observation of trion drift under continuous-wave excitation. Our findings provide a new route for manipulating trions and achieving new types of optoelectronic devices. Trion ; Exciton ; Electric field ; Monolayer ; Excitation ; Excited state ; Electron ; Semiconductor ; Condensed matter physics ; Physics ; Spin (aerodynamics) ; Atomic physics ; Materials science ; Optoelectronics ; Nanotechnology 2D Materials and Applications ; Molecular Junctions and Nanostructures ; Perovskite Materials and Applications
Authors: Madeline M. Evarts | Zachary H. Strong | Michael J. Krische
Source: Organic Letters (article, 2023-08-01)
Field: Chemistry — Organic Chemistry

Oxetane-, Azetidine-, and Bicyclopentane-Bearing <i>N</i>-Heterocycles from Ynones: Scaffold Diversification via Ruthenium-Catalyzed Oxidative Alkynylation A process for 3-fold scaffold diversification is achieved via ruthenium-catalyzed oxidative alkynylation of commercially available oxetanols, azetidinols and bicyclopentanols to form α,β-acetylenic ketones (ynones), which are subsequently converted to oxetane-, azetidine- and bicyclopentane-bearing pyrazoles, isoxazoles and pyrimidines. A one-pot oxidative alkynylation-condensation protocol that directly converts azetidinols to azetidine-substituted pyrazoles or pyrimidines is demonstrated. Chemistry ; Oxetane ; Ruthenium ; Catalysis ; Azetidine ; Oxidative phosphorylation ; Alkynylation ; Combinatorial chemistry ; Organic chemistry Catalytic C–H Functionalization Methods ; Synthesis and Catalytic Reactions ; Catalytic Alkyne Reactions
Authors: Francesco Basoccu | Federico Cuccu | Pietro Caboni | Lidia De Luca | Andrea Porcheddu
Source: Molecules (article, 2023-02-28)
Field: Chemistry — Organic Chemistry

Mechanochemistry Frees Thiourea Dioxide (TDO) from the ‘Veils’ of Solvent, Exposing All Its Reactivity The synthesis of nitrogen-based heterocycles has always been considered essential in developing pharmaceuticals in medicine and agriculture. This explains why various synthetic approaches have been proposed in recent decades. However performing as methods, they often imply harsh conditions or the employment of toxic solvents and dangerous reagents. Mechanochemistry is undoubtedly one of the most promising technologies currently used for reducing any possible environmental impact, addressing the worldwide interest in counteracting environmental pollution. Following this line, we propose a new mechanochemical protocol for synthesizing various heterocyclic classes by exploiting thiourea dioxide (TDO)'s reducing proprieties and electrophilic nature. Simultaneously exploiting the low cost of a component of the textile industry such as TDO and all the advantages brought by a green technique such as mechanochemistry, we plot a route towards a more sustainable and eco-friendly methodology for preparing heterocyclic moieties. Mechanochemistry ; Environmentally friendly ; Biochemical engineering ; Thiourea ; Reagent ; Green chemistry ; Nanotechnology ; Chemistry ; Organic chemistry ; Materials science ; Engineering ; Molecule ; Ecology ; Supramolecular chemistry Nanomaterials for catalytic reactions ; Advanced Photocatalysis Techniques ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Mark James Horgan | Lukas Zell | Bianka Siewert | Hermann Stuppner | Daniela Schuster | Veronika Temml
Source: Journal of Chemical Information and Modeling (article, 2023-09-29)
Field: Chemistry — Organic Chemistry

Identification of Novel β-Tubulin Inhibitors Using a Combined <i>In Silico</i>/<i>In Vitro</i> Approach Due to their potential as leads for various therapeutic applications, including as antimitotic and antiparasitic agents, the development of tubulin inhibitors offers promise for drug discovery. In this study, an <i>in silico</i> pharmacophore-based virtual screening approach targeting the colchicine binding site of β-tubulin was employed. Several structure- and ligand-based models for known tubulin inhibitors were generated. Compound databases were virtually screened against the models, and prioritized hits from the SPECS compound library were tested in an <i>in vitro</i> tubulin polymerization inhibition assay for their experimental validation. Out of the 41 SPECS compounds tested, 11 were active tubulin polymerization inhibitors, leading to a prospective true positive hit rate of 26.8%. Two novel inhibitors displayed IC<sub>50</sub> values in the range of colchicine. The most potent of which was a novel acetamide-bridged benzodiazepine/benzimidazole derivative with an IC<sub>50</sub> = 2.9 μM. The screening workflow led to the identification of diverse inhibitors active at the tubulin colchicine binding site. Thus, the pharmacophore models show promise as valuable tools for the discovery of compounds and as potential leads for the development of cancer therapeutic agents. Pharmacophore ; Tubulin ; In silico ; Virtual screening ; Drug discovery ; Computational biology ; Paclitaxel ; Chemistry ; Microtubule ; Combinatorial chemistry ; Pharmacology ; Stereochemistry ; Biochemistry ; Biology ; Cancer Synthesis and biological activity ; Click Chemistry and Applications ; Cancer therapeutics and mechanisms
Authors: Márcio José da Silva | Cláudio Júnior Andrade Ribeiro | Eduardo Nery de Araújo | Isadora Merighi Torteloti
Source: Processes (article, 2023-07-24)
Field: Chemistry — Organic Chemistry

Acetalization of Alkyl Alcohols with Benzaldehyde over Cesium Phosphomolybdovanadate Salts In this work, vanadium-substituted cesium phosphomolybdate salts with general formulae Cs3+nPMo12−nVnO40 (n = 0, 1, 2, and 3) were synthesized and evaluated in the acetalization of benzaldehyde with alkyl alcohols. All the catalysts were characterized through Raman, infrared, and ultraviolet–visible spectroscopies, powder X-ray diffraction patterns, isotherms of N2 desorption/adsorption, and measurements of acidity strength. The catalytic activity of cesium phosphomolybdovanadate salts was evaluated in the acetalization reactions of benzaldehyde with alkyl alcohols. Among the salts tested, the Cs4PMo11V1O40 was the most active and selective catalyst in the conversion of benzaldehyde to methyl benzyl acetal and benzoic acid, which was obtained without the use of an oxidant agent. The impact of the main reaction parameters on the conversion and selectivity was evaluated by varying the content of vanadium per heteropolyanion, catalyst load, temperature, and alkyl alcohols. The greatest activity of the Cs4PMo11V1O40 salt was assigned to the highest Brønsted acidity strength, as demonstrated by the acidity measurements and analysis of their surface properties. This solid catalyst has advantages over traditional liquid homogenous catalysts, such as low corrosiveness, a minimum generation of residues and effluents, and easy recovery/reuse. In addition, its synthesis route is easier and quicker than solid-supported catalysts and comprises a potential alternative route to synthesize acetals. Benzaldehyde ; Chemistry ; Catalysis ; Alkyl ; Vanadium ; Benzyl alcohol ; Salt (chemistry) ; Inorganic chemistry ; Alcohol ; Benzoic acid ; Adsorption ; Organic chemistry ; Nuclear chemistry Chemical Synthesis and Reactions ; Polyoxometalates: Synthesis and Applications ; Carbon dioxide utilization in catalysis