jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Davoud Balarak | Marzieh Baniasadi | Kethineni Chandrika
Source: International Journal of Life Science and Pharma Research (article, 2020-01-10)
Field: Chemistry — Organic Chemistry

Investigating the Efficiency of Zirconium Oxide Nanoparticles in Removal of Ciprofoxacin from Aqueous Environments Antibiotics as emerging contaminants are of global concern due to the development of antibiotic resistant genes potentially causing superbugs. The inefficiency of conventional purification processes in the complete removal of antibiotics increases the resistance of microorganisms in humans and the environment, hence new and low-cost technology is needed. Adsorptive materials have been extensively used for the conditioning, remediation and removal of inorganic and organic hazardous materials. Zirconium oxide is a widely used inorganic material which is chemically stable, non-toxic and not soluble in water. Thus it could be an attractive candidate for drinking water puri? cation. In this study, Zirconium Oxide Nanoparticles (ZrO2NP)has been used as the adsorbent for the possibility of removing Cipro? oxacin (CIP) from aqueous solution using the batch adsorption technique under different conditions of initial CIP concentration (25, 50, 75, 100 mg/L), adsorbent dose (0.1, 0.2, 0.3, 0.5, 0.7, 0.9 and 1 g/L) and contact time (10-150 min). The percentage of CIP adsorbed increased with increase in the mass of the adsorbent dose from 0.1 to 1 g/L. Kinetics study for sorption was evaluated using diffusion models, pseudo-first order kinetic and pseudo-second order kinetic. Results show that pseudo second-order kinetic model gave the best description for the adsorption process. The experiments showed that the highest removal rate was 96.5% under optimal conditions. The sorption of CIP on ZrO2NP was rapid during the first 30 min and the equilibrium attained within 75 min. The results suggest that ZrO2NPcould be a good candidate to remove CIP from wastewater containing different amounts of antibiotic. Adsorption ; Sorption ; Aqueous solution ; Chemistry ; Zirconium ; Water treatment ; Nanoparticle ; Human decontamination ; Kinetics ; Environmental remediation ; Nuclear chemistry ; Chemical engineering ; Contamination ; Materials science ; Inorganic chemistry ; Organic chemistry ; Waste management ; Environmental engineering ; Nanotechnology ; Environmental science Nanomaterials for catalytic reactions ; Adsorption and biosorption for pollutant removal ; Pharmaceutical and Antibiotic Environmental Impacts
Authors: Joshua Muir | Michael C. Jollands | Feiwu Zhang | Andrew Walker
Source:  (preprint, 2020-07-24)
Field: Materials Science — Biomaterials

Explaining the dependence of M-site diffusion in forsterite on silica activity: a Density Functional Theory approach Experimentally silica activity (aSiO2) has been shown to have an effect on Mg diffusion in forsterite but without any obvious mechanism. We calculated the effects of aSiO2 and aluminium content (the main contaminant in the experimental studies), and their co-effect, on Mg diffusion in forsterite, using thermodynamic minimisations of defect formation energies (calculated using Density Functional Theory (DFT)) and a Monte-Carlo diffusion model. These two variables, in isolation, do not appreciably change the defect concentrations of forsterite and thus do not affect the diffusivity of Mg. However, when elevated together, they cause large increases in the Mg vacancy content and thus can increase the Mg diffusivity by 1-6 orders of magnitude depending on temperature, with little pressure dependence. This effect is largely independent of Al2O3 concentration above ~1 wt. ppm, and thus, for all practical purposes, should occur wherever forsterite is in the presence of enstatite. It is also largely is dependent upon configurational entropy and is thus highly sensitive to the chemistry of the crystal. Small amounts of structurally bound hydroxyl groups at low temperatures (1000 K) suppresses this effect in perfect forsterite but it is likely robust in the presence of water when alternative water sinks (such as Ti or Fe) are present or at high temperatures (2000 K). This effect is also robust in the presence of ferrous iron (or other substitutional Mg defects) at all temperatures. Fe2O3 can operate like Al2O3 in this reaction and should enhance its effect. These findings explain the experimentally-observed dependency of diffusion of aSiO2, and elucidate how chemical activity variations in both experiments and natural settings could affect not only the diffusivity of Mg in forsterite, but of olivine-hosted cations in general. Forsterite ; Thermal diffusivity ; Diffusion ; Vacancy defect ; Thermodynamics ; Enstatite ; Chemistry ; Density functional theory ; Materials science ; Mineralogy ; Crystallography ; Computational chemistry ; Meteorite Clay minerals and soil interactions ; Metal Extraction and Bioleaching ; Minerals Flotation and Separation Techniques
Authors: Andreas Holm | Christoph Sprengard | Antoine Batard | Lukas Berger | Y. Carmi | Chiara Cucchi | Esra Kücükpinar | Alice Lorenzati | Oliver Miesbauer | Sebastian Treml | Bernard Yrieix
Source: Chalmers Research (Chalmers University of Technology) (article, 2020-01-01)
Field: Chemistry — Spectroscopy

Annex 65, Long-Term Performance of Super-Insulating-Materials in Building Components and Systems. Report of Subtask II: Scientific Information for Standardization Bodies dealing with Hygro-Thermo-Mechanical Properties and Ageing This subtask is divided in two actions:Action 2A: Materials Assessment &amp;amp; Ageing Procedures (Experiments &amp;amp; Simulation)Action 2B: Components &amp;amp; Systems Assessment (Experiments &amp;amp; Simulation)As their structures and microstructures are completely different, Super-Insulating Materials (SIMs) cannot be compared directly to traditional insulating materials. Worldwide acceptance of these materials will be improved if the hygro-thermal and mechanical properties of SIM can be clearly articulated and reproduced. In particular, nano-structured materials used to manufacture a SIM are characterized by a high specific area (m²/g) and narrow pores (smaller than 1 μm) which make them very sensitive to gas adsorption and condensation, especially in contact with water molecules.Therefore, methods of characterization must be adapted, or new methods developed to measure the microstructural, hygro-thermal and mechanical properties of these materials and their barrier films.In parallel, modelling methods to describe heat, moisture and air transfer through nano-structured materials and films will have to be developed (adsorption and desorption models, diffusion models, freeze-thawing …).Of course, a few methods will be common to all SIMs, but due to their structural differences some specific modelling methods have to be developed.SIMs can offer considerable advantages (low thickness, low Uvalue) ; however potential drawback effects should be considered in the planning process in order to optimise the development of these extraordinary properties (very low thermal conductivity) and to prevent negative publicity which could be detrimental to this sector of emerging products. This is why ageing tests will be set according to realistic conditions (temperature, moisture, pressure, load …) as set out in SubTask 3A. One objective of artificial ageing is to understand potential degradation processes that could occur. The durability of hydrophobic treatment is one of these processes and will also be subject to discussion and investigation.At the component scale, additional characterizations are needed as panels or rolls are sold by manufacturers. In particular, thermal bridges will be carefully investigated, as the extraordinary thermal performance of SIMs are sensitive to the influence of thermal bridges. Materials science ; Mechanical engineering ; Characterization (materials science) ; Thermal ; Standardization ; Thermal mass ; Process engineering ; Composite material ; Computer science ; Nanotechnology ; Engineering ; Thermodynamics Aerogels and thermal insulation
Authors: Dian-Qian Wang | Ying-Sheng Wang | Zuo-Xun Xie | Wei-Min Zhang
Source: International nano letters. (article, 2020-10-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Adsorption behaviors of methylene blue onto tubular cadmium sulfide polycrystals Adsorption ; Methylene blue ; Freundlich equation ; Materials science ; Enthalpy ; Mesoporous material ; Cadmium sulfide ; Langmuir ; Chemical engineering ; Langmuir adsorption model ; Diffusion ; Molecule ; Cadmium ; Nuclear chemistry ; Physical chemistry ; Organic chemistry ; Chemistry ; Thermodynamics ; Metallurgy ; Catalysis Gold and Silver Nanoparticles Synthesis and Applications ; Quantum Dots Synthesis And Properties ; Nanomaterials for catalytic reactions
Authors: Abdelmalek Bellal | Lemnouer Chibane
Source: International Journal of Chemical Reactor Engineering (article, 2020-08-31)
Field: Chemistry — Inorganic Chemistry

Fischer-Tropsch reaction mixture permeation through a silicalite-1 membrane reactor and its effect on the produced hydrocarbons distribution Abstract The quantification of the permeation of the Fischer-Tropsch reaction mixture through a silicalite-1 zeolite membrane in which is integrated in to fixed bed reactor was theoretically investigated. The approach is based on the prediction of the permeation parameters by using two different mechanisms including surface diffusion and gaseous diffusion. It was found that under our investigated conditions, the total permeation could be governed by surface diffusion model since the contribution of this mechanism is dominant versus the gaseous diffusion. Noteworthy, our results show that except for the selective gas permeation of carbon dioxide, the measuring factors of different permeates were proportional to the operating pressure. Hydrocarbons with low molecular weight diffuse greater than long-chain hydrocarbons. Furthermore, the high adsorbed molecules are more likely to be affected by the high processing temperature. It can be also highlighted that the permeate amounts has no important effect on the product distribution which is characterized by the olefins to paraffins ratios. So the assumption that considers the separation of CO 2 without assuming other components permeation is well supported. Permeation ; Chemistry ; Diffusion ; Membrane ; Adsorption ; Chemical engineering ; Product distribution ; Hydrocarbon ; Membrane reactor ; Zeolite ; Chromatography ; Analytical Chemistry (journal) ; Catalysis ; Thermodynamics ; Organic chemistry Zeolite Catalysis and Synthesis ; Catalysts for Methane Reforming ; Membrane Separation and Gas Transport
Authors: Wenlong Xu | Shuang Chen | Jinhong Zhang | Huie Liu | Jiameng Zhu | Shuai Diao | Anran Yu
Source: SHILAP Revista de lepidopterología (article, 2020-09-01)
Field: Chemistry — Spectroscopy

Preparation and adsorption of carboxymethyl cellulose graphene composite aerogels Cellulose graphene composite aerogels (CMC/GA) were prepared by one-step hydrothermal reaction based on graphite oxidation with the addition of low cost carboxymethyl cellulose. The functional group structure and microstructure of CMC/GA were characterized. The mechanism and capacity of the adsorption of Methylene Blue (MB) were investigated by CMC/GA in water. The results show that the higher temperature and higher initial concentration of MB are beneficial to the adsorption of CMC/GA. The adsorption isotherm is fitted with Langmuir model, the adsorption activation energy of the system is 57.951 kJ·mol<sup>-1</sup>, indicating that the adsorption of MB by CMC/GA is monolayer and belongs to chemical adsorption. The adsorption kinetics of MB is fitted with pseudo-second-order kinetics model. The intrapartical diffusion model of MB with different concentration shows that the adsorption process of CMC/GA for MB can be divided into two stages:macroporous diffusion and microporous diffusion, and the diffusion rate of macroporous diffusion is obviously higher than that of microporous diffusion. Carboxymethyl cellulose ; Materials science ; Graphene ; Composite number ; Adsorption ; Cellulose ; Composite material ; Chemical engineering ; Aerogel ; Nanotechnology ; Metallurgy ; Organic chemistry ; Chemistry ; Sodium Aerogels and thermal insulation
Authors: C. Montella
Source: Journal of Electroanalytical Chemistry (article, 2020-11-10)
Field: Chemistry — Electrochemistry

From the anomalous diffusion impedance to the closed-form, infinite-series and integral formulations of the voltammetric response of thin-film insertion materials under restricted diffusion conditions. A modelling contribution based on the anomalous mass transfer function Computation ; Laplace transform ; Linear sweep voltammetry ; Electrochemistry ; Diffusion ; Limiting current ; Mass transfer ; Integral equation ; Chemistry ; Thermodynamics ; Electrical impedance ; Mathematical analysis ; Mathematics ; Physics ; Electrode ; Cyclic voltammetry ; Physical chemistry ; Algorithm ; Quantum mechanics Electrochemical Analysis and Applications ; Conducting polymers and applications ; Advanced Chemical Sensor Technologies
Authors: Pandula Manura Liyanage
Source:  (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Multi-scale Modelling of Hydrogen Diffusion in Solids : Impact of Diffusion on Denuded Zones in Zr Alloy Pressure Vessels and Hydrogen Diffusion in Lead Zirconate Titanate. Zirconium alloys are used as cladding in nuclear reactors. They are vulnerable to hydrogen degradation under the harsh service conditions, which necessitates monitoring for the hydride contentHydride denuded zones found these pressure tubes hinders the monitoring process, which uses scrape samples taken from the pressure tubes. A hypothesis is proposed that oxygen slows the diffusion of hydrogen and thereby encourages the occurrence of hydride denuded zones. We developed an approach to determine the diffusivity of hydrogen in zirconium, combining of first principles calculations and kinetic Monte Carlo (KMC) simulations. Rate constants found through the energy landscapes of hydrogen motion between different interstitial sites, were used in KMC to determine the values of bulk diffusivity. We also found that hydrogen diffusivity in Zr is closely isotropic, with a slightly higher diffusivity in the C-axis direction. With this model we found that oxygen decreases the diffusivity of hydrogen for moderate oxygen concentrations. Though the diffusivity of H seems to be reduced by O, looking at the O concentration profiles found in pressure tubes, we see that the decrease is insufficient to cause a sufficient change to the size of hydrides. Hence, we reject the hypothesis as the main reason for the formation of denuded zones. Thereafter, we used the model to determine the effect of stress on diffusivity of H by applied hydrostatic stresses. We see a decrease in the diffusivity with increase in compressive stress showing us that stress does influence the diffusivity of H. The main reason for this decrease is the increase in activation barriers Lead Zirconate Titanate (PZT) is a widely used piezoelectric material which is also affected by H absorption. This gives the need of understanding the H diffusion in PZT. This research presents the initial results of a study which aims to simulate hydrogen diffusion in PZT using the validated diffusion model used for Zr. First-principles calculations were done to determine the possible hydrogen occupancy locations in the PZT lattice. These results will serve as a basis for future nudged elastic band calculations to determine the diffusion characteristics for H diffusion in PZT. Thermal diffusivity ; Hydrogen ; Hydride ; Diffusion ; Materials science ; Oxygen ; Thermodynamics ; Chemistry ; Zirconium ; Metallurgy Nuclear Materials and Properties ; Nuclear reactor physics and engineering ; Thermodynamic and Structural Properties of Metals and Alloys
Authors: Álvaro de Jesús Ruíz-Baltazar | Simón Yobanny Reyes‐López | Daniel Larrañaga Ordaz | Néstor Méndez‐Lozano | Marco Antonio Zamora-Antuñano | R. Pérez
Source: Preprints.org (preprint, 2020-07-11)
Field: Materials Science — Materials Chemistry

Magnetic Nanoparticles of Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; Biosynthesized by &lt;em&gt;Cnicus Benedictus&lt;/em&gt; Extract: Photocatalytic Study of Organic Dye Degradation and Antibacterial Behavior Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes, free of polluting substance has assumed a preponderant role. The aim of this work is propose a bioinspired, facile, at low cost, non-toxic and environmentally friendly alternative to obtaining magnetic nanoparticles whit a majority phase of magnetite (Fe3O4). Is important to empathize that the synthesis was based on the chemical reduction through the Cnicus Benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus Benedictus is abundant endemic plant in Mexico, with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe3O4 nanoparticles (Fe3O4 NP&amp;rsquo;s) was calculated by Williamson-Hall method. The photocatalytic properties of the Fe3O4 NP&amp;acute;s were studied by kinetics absorptions models in the Congo red (CR) degradation. Finally the antibacterial effect of the Fe3O4 NP&amp;acute;s were evaluated mediated the Kirby-Bauer method against E. coli and S. aureus bacteria. This route offers a green alternative to obtain Fe3O4 NP&amp;acute;s with remarkable magnetic, photocatalytic and antibacterial properties. Photocatalysis ; Nanoparticle ; Environmentally friendly ; Magnetite ; Crystallite ; Magnetic nanoparticles ; Nuclear chemistry ; Congo red ; Antibacterial activity ; Chemistry ; Materials science ; Chemical engineering ; Nanotechnology ; Degradation (telecommunications) ; Catalysis ; Bacteria ; Organic chemistry ; Metallurgy ; Biology ; Computer science Nanoparticles: synthesis and applications ; Water Quality Monitoring and Analysis
Authors: Grant C. Wallace
Source: Digital Commons - Montana Tech (Montana Tech of the University of Montana) (article, 2020-01-01)
Field: Chemistry — Inorganic Chemistry

SYNTHESIS OF CARBIDE CERAMICS VIA REDUCTION AND CARBURIZATION OF OXYANIONS ADSORBED ONTO AN ACTIVATED CARBON MATRIX Carbide ceramics rank high among the hardest and most chemically resistant materials. Their ability to resist physical and chemical attack under conditions where more traditional materials fail make them very desirable for a number of industrial applications. Their use is limited, however, due to the expensive and energy-intensive methods required to produce them commercially. A more versatile and energy-efficient process for commercial carbide production has been developed by synthesizing micron/sub-micron carbide ceramic particles through the adsorption and subsequent carburization of anions on an activated carbon matrix. Oxyanion solutions containing sodium tungstate, sodium molybdate, or sodium metasilicate are adsorbed onto activated carbon to produce anion-loaded precursors. These precursors are carburized in the presence of a reducing atmosphere consisting of hydrogen, carbon monoxide, and methane to produce carbide crystals on the activated carbon surface. In this study, tungstate (WO42-), molybdate (MoO42-), and silicate (SiO32-) anions were evaluated. Silicon carbide (SiC) whiskers and mixed crystals of tungsten carbide (WC), tungsten semicarbide (W2C), and tungsten (W) were formed via carbothermal reduction using inert and reducing gas atmospheres at temperatures much lower than current commercial practice. Mixed crystals of WC, W2C, and W were synthesized at 950 °C under an atmosphere of 80% CH4, 10% H2, and 10% CO. Molybdenum carbide (Mo2C) was synthesized at temperatures as low as 850oC under an atmosphere consisting of 80% CH4, 10% CO, and 10% H2. Under optimal conditions, conversion to Mo2C and WC exceeded 90%. SiC was synthesized at temperatures as low as 1200 °C under H2. Separation of the WC/W2C/W crystals from the activated carbon matrix has been demonstrated using surfactant-aided density separation methods. Response surface modeling was used to determine optimal conditions for tungstate, molybdate, and silicate adsorption as well as the optimal carburization conditions for the W-loaded and Mo-loaded precursors. Results show that the carburization process is feasible and that it is possible to mathematically model and statistically optimize the production and carburization of the activated carbon precursors. Carbide ; Adsorption ; Activated carbon ; Ceramic matrix composite ; Materials science ; Ceramic ; Matrix (chemical analysis) ; Carbon fibers ; Reduction (mathematics) ; Chemistry ; Chemical engineering ; Metallurgy ; Composite material ; Organic chemistry ; Composite number ; Mathematics ; Engineering Pigment Synthesis and Properties
Authors: Zhihong Wang | She Zhigang | Mijun Peng | Qiuling Yang | Tao Huang
Source: BioResources (article, 2020-11-24)
Field: Chemistry — Inorganic Chemistry

Determining the adsorption and desorption properties of flavonoids found in Eucommia ulmoides Oliv. leaves using macroporous resin and acetylcholinesterase inhibitor screening The adsorption and desorption properties of 12 resins containing flavonoid compounds found in Eucommia ulmoides Oliv. leaves (EUOL) extracts were investigated. The static adsorption and desorption, kinetic, adsorption, and thermodynamic properties of the adsorption of the flavonoids onto macroporous resins were determined. The HPD-300, NKA-9, and AB-8 resins exhibited a greater adsorption capacity and desorption characteristics. A pseudo-second-order kinetic model was suitable to characterize the kinetics of the adsorption of flavonoids onto the resins selected, and the diffusion of flavonoids was divided into three stages, with the boundary layer diffusion and intra-particle diffusion being the rate-controlling factors. The Langmuir model was found to be the best description of the adsorption behavior of flavonoids. Thermodynamic studies indicated that the adsorption of flavonoids was a physical, exothermic, and spontaneous process. The 60% ethanol eluted fraction from the NKA-9 resin column not only had the highest flavonoid content, but also possessed the strongest inhibitory effect on acetylcholinesterase. In addition, the degree of binding of the main flavonoid compounds found in the EUOL to acetylcholinesterase compounds was investigated via molecular docking technology. The results showed that the docking total score of isoquercetin and enzyme proteins were the highest, followed by kaempferol-3-O-rutinoside. Adsorption ; Eucommia ulmoides ; Desorption ; Flavonoid ; Chemistry ; Chromatography ; Kaempferol ; Organic chemistry ; Nuclear chemistry ; Antioxidant Zeolite Catalysis and Synthesis ; Natural product bioactivities and synthesis ; Biological Activity of Diterpenoids and Biflavonoids
Authors: Zhanyao Hou | Ken Broeckhoven | Gert Desmet | Frédéric Lynen
Source: Journal of Chromatography A (article, 2020-12-28)
Field: Chemistry — Spectroscopy

Through-pore polymerization in polar high-performance liquid chromatography columns allowing scanning electron microscopy based imaging of the packing order Chemistry ; Scanning electron microscope ; Polymerization ; Chromatography ; Polar ; Microscopy ; High-performance liquid chromatography ; Chemical engineering ; Polymer ; Organic chemistry ; Optics Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications ; Metabolomics and Mass Spectrometry Studies