jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Nosair El Yakoubi | Zineb Nejjar El Ansari | Mounia Ennami | Mohammed L’bachir El Kbiach | Loubna Bounab | Brahim El Bouzdoudi
Source: Journal of Ecological Engineering (article, 2023-12-30)
Field: Materials Science — Materials Chemistry

Biosorption of Hexavalent Chromium Cr(VI) onto Ziziphus Lotus Fruits Powder: Kinetics, Equilibrium, and Thermodynamics Ziziphus lotus has been the subject of several researchs because of its nutritional benefits and ecological attributes. The removal of hexavalent chromium Cr(VI) from a solution using powdered Zizphus lotus fruits, for its qualities of being inexpensive as well as environmentally friendly, was investigated. The results obtained showed that at pH=2, at 30°C, after 600 min of adsorbent/adsorbate contact, with 100 mg/L as initial concentration of Cr(VI) and a biosorbent dosage of 5 g/ L, the biosorption of Cr (VI) on Zizphus lotus fruit powder (ZLFP) is at its maximum rate. The sorption process was exothermic (∆H° = - 6.69 kJ/mol), and was characterized by a positive entropy values (∆S° = 46.76 J/K mol) suggesting a high affinity of the ZLFP for Cr (VI). Given that the Gibbs free energy (∆G°) is negative and decreases as temperatures increase from 293 to 323 K, the process of biosorption is both feasible and spontaneous. The Temkin model and the Langmuir model both generated excellent fits to the equilibrium data. The maximum monolayer biosorption capacity was 36.11 mg/g. The pseudo second order model was used to fit the kinetic data relating to the adsorption of Cr (VI) on the FP. The FTIR spectral analysis allowed the characterization of the biochemical groups mainly involved in the sorption of Cr (VI) ions on the ZLFP, and which are : N–C, H-O, O–C, H-C, and O=C. The capacity of Ziziphus lotus fruit (ZLFP) as an inexpensive, effective, and ecofriendly biosorbent is confirmed through this study. Biosorption ; Hexavalent chromium ; Kinetics ; Chromium ; Lotus ; Chemistry ; Ziziphus ; Nuclear chemistry ; Materials science ; Metallurgy ; Botany ; Adsorption ; Physics ; Physical chemistry ; Biology ; Sorption Pickering emulsions and particle stabilization ; Adsorption and biosorption for pollutant removal
Authors: David Patiño‐Ruiz | Lars Rehmann | Mehrab Mehrvar | Édgar Quiñones-Bolaños | Adriana Herrera
Source:  (preprint, 2023-07-17)
Field: Chemistry — Organic Chemistry

Synthesis of FeO@SiO2-DNA core-shell engineered nanostructures for rapid adsorption of heavy metals in aqueous solutions &lt;p&gt;Creating novel and innovative nanostructures is a challenge, aiming to discover nanomaterials with promising properties for environmental remediation. In this study, the physicochemical and adsorption properties of a heterogeneous nanostructure are evaluated for the rapid removal of heavy metal ions from aqueous solutions. Core–shell nanostructures are prepared using iron oxide cores and silica dioxide shells. The core is synthesized &lt;em&gt;via&lt;/em&gt; the co-precipitation method and modified &lt;em&gt;in situ&lt;/em&gt; with citric acid to grow a carboxyl layer. The shell was hydrolyzed/condensed and then functionalized with amine groups for ds-DNA condensation &lt;em&gt;via&lt;/em&gt; electrostatic interaction. The characterization techniques revealed functional FeO@SiO2–DNA nanostructures with good crystallinity and superparamagnetic response (31.5 emu g−1). The predominant superparamagnetic nature is attributed to the citric acid coating. This improves the dispersion and stability of the magnetic cores through the reduction of the dipolar–dipolar interaction and the enhancement of the spin coordination. The rapid adsorption mechanism of FeO@SiO2–DNA was evaluated through the removal of Pb(II), As(III), and Hg(II). A rapid adsorption rate is observed in the first 15 min, attributed to a heterogeneous chemisorption mechanism based on electrostatic interactions. FeO@SiO2–DNA shows higher adsorption efficiency of 69% for Pb(II) removal compared to As(III) (51%) and Hg(II) (41%). The selectivity towards Pb(II) is attributed to the similar acid nature to ds-DNA, where the ionic strength interaction provides good affinity and stability. The facile synthesis and rapid adsorption suggest a promising nanostructure for the remediation of water sources contaminated with heavy metal ions and can be extended to other complex molecules.&lt;/p&gt; Adsorption ; Aqueous solution ; Chemistry ; Superparamagnetism ; Inorganic chemistry ; Chemical engineering ; Metal ions in aqueous solution ; Metal ; Organic chemistry ; Magnetization Nanomaterials for catalytic reactions ; Advanced biosensing and bioanalysis techniques ; Synthesis of Tetrazole Derivatives
Authors: Tobias Frohoff-Hülsmann | Uwe Thiele
Source: arXiv (Cornell University) (preprint, 2023-01-13)
Field: Materials Science — Materials Chemistry

Nonreciprocal Cahn-Hilliard model emerges as a universal amplitude equation Oscillatory behavior is ubiquitous in out-of-equilibrium systems showing spatio-temporal pattern formation. Starting from a linear large-scale oscillatory instability -- a conserved-Hopf instability -- that naturally occurs in many active systems with two conservation laws, we derive a corresponding amplitude equation. It belongs to a hierarchy of such universal equations for the eight types of instabilities in homogeneous isotropic systems resulting from the combination of three features: large-scale vs.\ small-scale instability, stationary vs.\ oscillatory instability, and instability without and with conservation law(s). The derived universal equation generalizes a phenomenological model of considerable recent interest, namely, the nonreciprocal Cahn-Hilliard model, and may be of a similar relevance for the classification of pattern forming systems as the complex Ginzburg-Landau equation. Instability ; Cahn–Hilliard equation ; Isotropy ; Conservation law ; Amplitude ; Hierarchy ; Scale (ratio) ; Physics ; Statistical physics ; Pattern formation ; Homogeneous ; Mathematics ; Mathematical analysis ; Mechanics ; Law ; Differential equation ; Quantum mechanics Solidification and crystal growth phenomena ; Nonlinear Dynamics and Pattern Formation ; Advanced Mathematical Modeling in Engineering
Authors: Amalachukwu Ifeyinwa | Vincent Ismael Egbulefu Ajiwe | Nkiruka Charity Eboagu | Ifeoma Lilian Ekene-Echerebo | Chidinma Malinda Muobike
Source: World Journal of Applied Chemistry (article, 2023-05-18)
Field: Materials Science — Surfaces, Coatings and Films

Mann’s Cucumeropsis Seed Shell as an Oil Sorbent: Kinetic, Isotherm, and Thermodynamic Studies Oil spill cleanup using agricultural wastes, which otherwise cause environmental contamination, has gained popularity. In this study, the feasibility of using Mann's cucumeropsis seed shell, a commonly found agricultural waste, as an oil spill mop, was investigated. To identify the surface characteristics of the seed shell, SEM and BET analyses were employed. Batch crude oil sorption tests were performed under various adsorption conditions to determine the effects of initial oil concentration, contact time, adsorption temperature, and adsorbent dosage. Kinetic study of the sorption process involved the pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion models. Isotherm analysis involved the Langmuir, Temkin, Freundlich, and Dubinin-Radushkevich isotherms. Additionally, the thermodynamic parameters for the sorption process were established. SEM analysis revealed the porous nature of the seed shell's surface. The BET surface area was 313.2 m<sup>2</sup>/g. The oil sorption process conformed best to the pseudo-first-order kinetics and Langmuir isotherm. The monolayer sorption capacity of the seed shell was 13.072 g/g. The sorption process was exothermic, with some order at the adsorbent–mixture interface. The study's findings demonstrate that Mann's cucumeropsis seed shell is a potent oil sorbent that is safe for the environment and can be enhanced for use in cleaning up oil spills. Sorption ; Sorbent ; Adsorption ; Freundlich equation ; Langmuir ; Chemistry ; Langmuir adsorption model ; Monolayer ; Chemical engineering ; Chromatography ; Environmental chemistry ; Nuclear chemistry ; Organic chemistry Surface Modification and Superhydrophobicity
Authors: Katie Levey | Martin A. Edwards | Henry White | Julie V. Macpherson
Source: ChemRxiv (preprint, 2023-01-11)
Field: Chemistry — Electrochemistry

Simulation of the Cyclic Voltammetric Response of an Outer-Sphere Redox Species with Inclusion of Electrical Double Layer Structure and Ohmic Potential Drop A finite-element model has been developed to simulate the cyclic voltammetric (CV) response of a planar electrode for a 1e outer-sphere redox process, which fully accounts for cell electrostatics, including ohmic potential drop, ion migration, and the structure of the potential-dependent electric double layer. Both reversible and quasi-reversible redox reactions are treated. The simulations compute the time-dependent electric potential and ion distributions across the entire cell during a voltammetric scan. In this way, it is possible to obtain the interdependent faradaic and non-faradaic contributions to a CV and rigorously include all effects of the electric potential distribution on the rate of electron transfer and the local concentrations of the redox species Oz and Rz-1. Importantly, we demonstrate that the driving force for electron transfer can be different to the applied potential when electrostatic interactions are included. We also show that the concentrations of Oz and Rz-1 at the plane of electron transfer (PET) significantly depart from those predicted by the Nernst equation, even when the system is characterised by fast electron transfer/diffusion control. A mechanistic rationalisation is presented as to why the electric double layer has a negligible effect on the CV response of such reversible systems. In contrast, for quasi-reversible electron transfer the concentrations of redox species at the PET are shown to play an important role in determining CV wave shape, an effect also dependant on the charge of the redox species and the formal electrode potential of the redox couple. Failure to consider electrostatic effects could lead to incorrect interpretation of electron-transfer kinetics from the CV response. Simulated CVs at scan rates between 0.1 and 1000 V/s are found to be in good agreement with experimental data for the reduction of 1.0 mM Ru(NH3)63+ at a 2-mm diameter gold disk electrode in 1.0 M potassium nitrate. Redox ; Electron transfer ; Chemistry ; Ohmic contact ; Electrode potential ; Nernst equation ; Electrode ; Electric potential ; Chemical physics ; Standard electrode potential ; Analytical Chemistry (journal) ; Ion ; Electrochemistry ; Molecular physics ; Inorganic chemistry ; Physical chemistry ; Voltage ; Physics ; Chromatography Electrochemical Analysis and Applications ; Electrocatalysts for Energy Conversion ; Electrochemical sensors and biosensors
Authors: A. Mangayarkarasi | S. Arivoli | K. Veeravelan
Source: Ecology Environment and Conservation (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

Lagenaria siceraria Stem Nano Carbon Adsorption Kinetics and Thermodynamics of Malachite Green Dye Among the most significant industrial pollutants are dyes, notably in the textile industry. Many techniques have been put forth to remove colour from wastewater, but adsorption is the most widely accepted since it can be applied on a broad scale. The Malachite Green dye has been removed from aqueous settings using this work’s application of Modified Activated Lagenaria siceraria Stem Nano Carbon (ALSNC). The effects of pH, contact time, starting concentration, and adsorbent quantity were taken into account. Pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic models were among those utilised to examine the mechanism of the adsorption process. Additionally, equilibrium data was fitted to the Radlich-Peterson isotherm model as well as the Langmuir, Freundlich, and Dubinin-Radushkevich, isotherm models. As a result of raising initial dye concentration, pH, and contact duration, the Malachite Green’s ability to bind to surfaces was improved, according to the results. pH 9 was the ideal level. Malachite Green dye adsorption had a qmax of 15.87 mg/g according to the Langmuir model. The Freundlich isotherm model and the pseudo-second order kinetic model obtained the best fitness when taking into account the values of R2 (0.999) and 2. This work has shown that ALSNC can be used as a cost-effective and efficient adsorbent for the removal of Malachite Green from aquatic environments Malachite green ; Freundlich equation ; Adsorption ; Langmuir ; Chemistry ; Activated carbon ; Brilliant green ; Chemical engineering ; Organic chemistry Pigment Synthesis and Properties ; Synthesis of Tetrazole Derivatives ; Water and Wastewater Treatment
Authors: Johannes Mich | Daniel Braig | Tobias Gustmann | Christian Hasse | Arne Scholtissek
Source: arXiv (Cornell University) (preprint, 2023-04-28)
Field: Materials Science — Materials Chemistry

A comparison of mechanistic models for the combustion of iron microparticles and their application to polydisperse iron-air suspensions Metals can serve as carbon-free energy carriers, e. g. in innovative metal-metal oxide cycles as proposed by Bergthorson (Prog. Energy Combust. Sci., 2018). Iron powder is a suitable candidate since it can be oxidized with air. Nevertheless, the combustion of iron powder in air is challenging especially with respect to flame stabilization which depends on the particle size distribution among other factors. Models for the prediction of reaction front speed in iron-air suspensions can contribute to overcoming this challenge. To this end, three different models for iron particle oxidation are integrated into a laminar flame solver for simulating reaction fronts. The scientific objective of this work is to elucidate the influence of polydispersity on the reaction front speed, which is still not satisfactorily understood. In a systematic approach, cases with successively increasing complexity are considered: From single particle combustion to iron-air suspensions prescribing binary particle size distributions (PSDs), generic PSDs, and a PSD measured for a real iron powder sample. The simulations show that, dependent on the PSD, particles undergo thermochemical conversion in a sequential manner according to their size and every particle fraction exhibits an individual combustion environment. The local environment can be leaner or richer than the overall iron-to-air ratio would suggest and can be very different from single particle experiments. The contribution of individual particle fractions to the overall reaction front speed depends on its ranking within the PSD. The study further demonstrates, that although the three particle models show good agreement for single particle combustion, they lead to very different reaction front speeds. This is due to the different ignition behavior predicted by the particle models, which is shown to strongly influence the reaction front characteristics. Combustion ; Dispersity ; Particle (ecology) ; Materials science ; Particle size ; Laminar flow ; Iron oxide ; Mechanics ; Chemical engineering ; Chemistry ; Metallurgy ; Physics ; Physical chemistry ; Engineering Thermal and Kinetic Analysis ; Thermochemical Biomass Conversion Processes ; Coagulation and Flocculation Studies
Authors: Juan Arcenegui-Troya | Antonio Perejón | Pedro E. Sánchez‐Jiménez | Luis A. Pérez‐Maqueda
Source: Materials (article, 2023-02-23)
Field: Materials Science — Materials Chemistry

Flexible Kinetic Model Determination of Reactions in Materials under Isothermal Conditions Kinetic analysis remains a powerful tool for studying a large variety of reactions, which lies at the core of material science and industry. It aims at obtaining the kinetic parameters and model that best describe a given process and using that information to make reliable predictions in a wide range of conditions. Nonetheless, kinetic analysis often relies on mathematical models derived assuming ideal conditions that are not necessarily met in real processes. The existence of nonideal conditions causes large modifications to the functional form of kinetic models. Therefore, in many cases, experimental data hardly obey any of these ideal models. In this work, we present a novel method for the analysis of integral data obtained under isothermal conditions without any type of assumption about the kinetic model. The method is valid both for processes that follow and for those that do not follow ideal kinetic models. It consists of using a general kinetic equation to find the functional form of the kinetic model via numerical integration and optimization. The procedure has been tested both with simulated data affected by nonuniform particle size and experimental data corresponding to the pyrolysis of ethylene-propylene-diene. Kinetic energy ; Isothermal process ; Work (physics) ; Thermodynamics ; Range (aeronautics) ; Experimental data ; Kinetic theory ; Statistical physics ; Applied mathematics ; Computer science ; Materials science ; Physics ; Mathematics ; Classical mechanics Thermal and Kinetic Analysis ; Energetic Materials and Combustion ; Thermochemical Biomass Conversion Processes
Authors: Saurav Sharma | Cosmin Anitescu | Timon Rabczuk
Source: arXiv (Cornell University) (preprint, 2023-11-25)
Field: Materials Science — Materials Chemistry

A discontinuous Galerkin method based isogeometric analysis framework for flexoelectricity in micro-architected dielectric solids Flexoelectricity - the generation of electric field in response to a strain gradient - is a universal electromechanical coupling, dominant only at small scales due to its requirement of high strain gradients. This phenomenon is governed by a set of coupled fourth-order partial differential equations (PDEs), which require $C^1$ continuity of the basis in finite element methods for the numerical solution. While Isogeometric analysis (IGA) has been proven to meet this continuity requirement due to its higher-order B-spline basis functions, it is limited to simple geometries that can be discretized with a single IGA patch. For the domains, e.g., architected materials, requiring more than one patch for discretization IGA faces the challenge of $C^0$ continuity across the patch boundaries. Here we present a discontinuous Galerkin method-based isogeometric analysis framework, capable of solving fourth-order PDEs of flexoelectricity in the domain of truss-based architected materials. An interior penalty-based stabilization is implemented to ensure the stability of the solution. The present formulation is advantageous over the analogous finite element methods since it only requires the computation of interior boundary contributions on the boundaries of patches. As each strut can be modeled with only two trapezoid patches, the number of $C^0$ continuous boundaries is largely reduced. Further, we consider four unique unit cells to construct the truss lattices and analyze their flexoelectric response. The truss lattices show a higher magnitude of flexoelectricity compared to the solid beam, as well as retain this superior electromechanical response with the increasing size of the structure. These results indicate the potential of architected materials to scale up the flexoelectricity to larger scales, towards achieving universal electromechanical response in meso/macro scale dielectric materials. Isogeometric analysis ; Flexoelectricity ; Discretization ; Finite element method ; Truss ; Discontinuous Galerkin method ; Galerkin method ; Basis function ; Partial differential equation ; Mathematical analysis ; Mathematics ; Computation ; Physics ; Dielectric ; Structural engineering ; Algorithm ; Engineering Nonlocal and gradient elasticity in micro/nano structures ; Advanced Numerical Analysis Techniques ; Numerical methods in engineering
Authors: Pengda Li | Qiantao Lei | Heyao Zhang | Mingbo Qi | Jinliang Song | Pengfei Lian | Jinxing Cheng | Qingbo Wang | Zhongfeng Tang | Zhanjun Liu
Source: Preprints.org (preprint, 2023-09-29)
Field: Materials Science — Materials Chemistry

Measurement of the Diffusion Coefficient of Xenon in Self-Sintered Nanopore Graphite for Molten Salt Reactor The economics and safety of reactors can be affected by the diffusion of fission products into graphite. Xenon (Xe) fission products diffusing into the graphite is the most critical neutron absorber and poison that can slow down or stop the chain reaction. The transport parameters for inhibiting the xenon diffusion in graphite are therefore the utmost scientific problem. Self-sintered nanopore-isotropic (~ 40nm) graphite (SSNG) derived from green pitch coke can decrease Xe diffusion into the graphite. In this study, a method for measurement of diffusion coefficients of fission products diffusion in graphite by Rutherford backscattering spectrometry (RBS) was reported. The SSNG substrates were implanted with Xe at a dose of 4.8×1015 ions/cm2 and energy of 7 MeV. The RT-implanted samples were annealed in a vacuum at 650°C for 9 h. The implanted and annealed samples were characterized by RBS. The diffusion coefficient D(Xe,650°C) is 6.49×10-20 m2/s. The results indicate the excellent ability to inhibit Xe diffusion of the SSNG and present significance in designing and evaluating the safety of nuclear reactors. Graphite ; Xenon ; Diffusion ; Materials science ; Fission products ; Radiochemistry ; Analytical Chemistry (journal) ; Ion ; Xenon-135 ; Nuclear graphite ; Neutron ; Fission ; Nuclear physics ; Chemistry ; Fission product yield ; Composite material ; Thermodynamics ; Chromatography Graphite, nuclear technology, radiation studies ; Nuclear reactor physics and engineering ; Nuclear Materials and Properties
Authors: Lei Wang | Masayuki Okugawa | Hirokazu Konishi | Yuheng Liu | Yuichiro Koizumi | Takayoshi Nakano
Source: Materials (article, 2023-08-03)
Field: Materials Science — Materials Chemistry

Fusion of Ni Plating on CP-Titanium by Electron Beam Single-Track Scanning: Toward a New Approach for Fabricating TiNi Self-Healing Shape Memory Coating The limited wear resistance of commercially pure titanium (CP-Ti) hinders its use in abrasive and erosive environments, despite its good strength-weight ratio and corrosion resistance. This paper reports the first study proposing a novel method for wear-resistant TiNi coating through Ni plating and electron beam (EB) irradiation in an in situ synthetic approach. Single-track melting experiments were conducted using the EB to investigate the feasibility of forming a TiNi phase by fusing the Ni plate with the CP-Ti substrate. Varying beam powers were employed at a fixed scanning speed to determine the optimal conditions for TiNi phase formation. The concentration of the melt region was found to be approximate as estimated from the ratio of the Ni-plate thickness to the depth of the melt region, and the region with Ni-48.7 at.% Ti was successfully formed by EB irradiation. The study suggests that the mixing of Ti atoms and Ni atoms was facilitated by fluid flow induced by Marangoni and thermal convections. It is proposed that a more uniform TiNi layer can be achieved through multi-track melting under appropriate conditions. This research demonstrates the feasibility of utilizing EB additive manufacturing as a coating method and the potential for developing TiNi coatings with shape memory effects and pseudoelasticity. Materials science ; Coating ; Marangoni effect ; Scanning electron microscope ; Composite material ; Substrate (aquarium) ; Shape-memory alloy ; Titanium ; Nickel titanium ; Plating (geology) ; Abrasive ; Metallurgy Shape Memory Alloy Transformations ; High Entropy Alloys Studies ; Advanced Memory and Neural Computing