jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hemant Kumar Nirala | Ameer Azam
Source: Journal of Survey in Fisheries Sciences (review, 2021-07-03)
Field: Chemistry — Organic Chemistry

Role of Green Chemistry in Synthesizing Magnetite Nanoparticles for Efficient Arsenic Adsorption: A Comprehensive Review This study investigates the adsorption behavior of arsenic species (As(III) and As(V)) over a broad pH range (2 to 13.7) and the efficacy of magnetite nanoparticles synthesized via green and conventional methods for arsenic removal from groundwater. Experimental results revealed distinct pH-dependent adsorption patterns for arsenic species: As(III) exhibited maximum adsorption near pH 8, whereas As(V) adsorbed predominantly around pH 4. At extremely low pH (2), both arsenic forms demonstrated minimal adsorption, while their conjugate base forms such as AsO3− and AsO43− showed enhanced adsorption at alkaline pH (13.5), indicating a strong influence of speciation and electrostatic interactions on removal efficiency. Ionic constituents in aqueous media, such as Cl−, HCO3−, H2PO4−, and SiO32−, facilitated adsorption, with cations like Na+, Mg2+, and Ca2+ further enhancing the process by altering surface charge dynamics of the adsorbents. To develop cost-effective and sustainable adsorbents, magnetite nanoparticles were synthesized using onion peel (MNp-OP) and corn silk extract (MNp-CS), and compared with conventionally synthesized magnetite (MNp-CO). The green extracts were characterized for their antioxidant capacity using FRAP and DPPH assays, confirming high phenolic, flavonoid, and tannin content. Characterization of the nanoparticles through SEM/EDS, XRD, FTIR, and BET surface analysis demonstrated crystalline magnetite structure with high specific surface areas of 243 m²/g (MNp-OP) and 261 m²/g (MNp-CS). Adsorption experiments revealed that arsenic removal by these nanoparticles follows chemisorption, intraparticle diffusion, and external diffusion mechanisms. The maximal adsorption capacities for MNp-OP, MNp-CS, and MNp-CO were found to be 1.86, 2.79, and 1.30 mg/g, respectively, highlighting the superior performance of green-synthesized materials. These findings suggest that MNp-OP and MNp-CS are not only environmentally benign but also highly efficient adsorbents, offering a promising solution for mitigating arsenic contamination in groundwater. Keywords: Arsenic adsorption, pH dependence, Magnetite nanoparticles, Green synthesis, Groundwater treatment Magnetite Nanoparticles ; Magnetite ; Adsorption ; Arsenic ; Nanoparticle ; Chemistry ; Nanotechnology ; Environmental chemistry ; Materials science ; Magnetic nanoparticles ; Metallurgy ; Physical chemistry ; Organic chemistry Nanomaterials for catalytic reactions ; Arsenic contamination and mitigation ; Adsorption and biosorption for pollutant removal
Authors: Mustafa Khawaja
Source:  (preprint, 2021-05-22)
Field: Chemistry — Spectroscopy

Molecular and Thermal Diffusion Coefficients Of n-Dodecane, Isobutylbenzene and Tetrahydronaphtalene Hydrocarbon Mixtures in Porous Media The thermal diffusion phenomenon was studied in detail by utilizing mixtures consisting of normal alkenes and two aromatics (n-Dodecane, Isobutylbenzene and 1,2,3,4-Tetrahydronaphtalene) based on comparison with available experimental data. This study presents the first report of a comparison of thermal diffusion coefficients of a ternary hydrocarbon mixture with experimental data in the literature. In addition to thermal diffusion coefficients, molecular diffusion coefficients are also measured and compared with Benchmark experimental values for three binary mixtures. Furthermore, molecular and thermal diffusion coefficients for three binary mixtures are used to correlate and estimate the thermal diffusion coefficients in the ternary hydrocarbon mixture. The thermo-solutal convection in porous media was simulated numerically using the Firoozabadi model in order to investigate the composition variation due to the processes of thermal diffusion and convection. Finally, a multi-porosity/multi-permeability model was utilized to further analyze the processes of thermal diffusion and convection in fractured porous media. Thermodynamics ; Diffusion ; Porous medium ; Ternary operation ; Dodecane ; Thermal ; Hydrocarbon ; Molecular diffusion ; Materials science ; Thermal diffusivity ; Porosity ; Convection ; Hydrocarbon mixtures ; Chemistry ; Organic chemistry ; Composite material ; Physics Diffusion Coefficients in Liquids ; NMR spectroscopy and applications ; Petroleum Processing and Analysis
Authors: V.L. Poliakov
Source: Reports of the National Academy of Sciences of Ukraine (article, 2021-08-26)
Field: Chemistry — Physical and Theoretical Chemistry

Dynamic linear adsorption with solid adsorbent material A mathematical problem of linear physical adsorption of a dissolved impurity is formulated, by consider-ing its diffusion transfer during the filtration of an aqueous suspension through a uniform adsorbent bed at a constant rate. By averaging the impurity concentrations in the free and bound states over an arbi-trary time period, an approximate solution of the problem is obtained, which is only expressed in terms of the elementary functions. On its basis, it is proposed to calculate the rational duration of the filter run. The solution is discussed and illustrated with a number of examples with typical input data. Adsorption ; Filtration (mathematics) ; Impurity ; Suspension (topology) ; Aqueous solution ; Diffusion ; Thermodynamics ; Chemistry ; Mathematics ; Filter (signal processing) ; Constant (computer programming) ; Materials science ; Mathematical analysis ; Applied mathematics ; Chromatography ; Physics ; Physical chemistry ; Organic chemistry ; Computer science ; Statistics Electrostatics and Colloid Interactions ; Groundwater flow and contamination studies ; Advanced Mathematical Modeling in Engineering
Authors: Tim Tichter | Rohan Borah | Thomas Nann
Source: arXiv (Cornell University) (preprint, 2021-04-26)
Field: Materials Science — Polymers and Plastics

A Theoretical Framework for the Electrochemical Characterization of\n Anisotropic Micro-Emulsions Micro emulsions (MEs) offer an exceptionally broad spectrum of applications\ncovering sensing, electrosynthesis, supercapacitors and redox-flow batteries.\nHerein, we develop the theory for a sophisticated electrochemical\ncharacterizion of MEs with a spatially and time-invariant anisotropy in the\ndiffusion domain by means of cyclic voltammerty (CV). By introducing spatially\ndependent diffusion coefficients into Ficks' first law, we derive a modified\ndiffusion equation to simulate any inherent anisotropy of the ME under\ninvestigation. Moreover, by formulating an extended second-order homogeneous\nsix-member square scheme for a kinetically controlled two-step two-electron\nreaction we capture the intricate entanglement of chemical and electrochemical\nequilibria. Our theoretical concept is finally validated by experimental CV\ndata for the ME based two-step redox reaction of methyl-viologen which paves\nthe way for a quantitative electrochemical characterization MEs.\n Electrochemistry ; Electrosynthesis ; Redox ; Anisotropy ; Characterization (materials science) ; Supercapacitor ; Materials science ; Diffusion ; Homogeneous ; Nanotechnology ; Chemistry ; Chemical physics ; Physics ; Thermodynamics ; Physical chemistry ; Electrode ; Quantum mechanics Conducting polymers and applications ; Electrocatalysts for Energy Conversion ; Advanced battery technologies research
Authors: Daniel R. Jones | Charles W. Dunnill
Source: ChemRxiv (preprint, 2021-01-11)
Field: Materials Science — Polymers and Plastics

Electrochemical Characterisations to Elucidate the Pseudocapacitance Mechanisms of a CdS/WOx Nanocomposite Photoanode in Acidic Aqueous Electrolytes &lt;p&gt;The electrochemical properties of a cadmium sulphide/tungsten(VI) sub-oxide (CdS/WO&lt;sub&gt;x&lt;/sub&gt;) nanocomposite have been explored using aqueous solutions of acetic acid (pH 2.2) and acidified sodium acetate (pH 5.0), for the purpose of evaluating the origin of pseudocapacitance within the material. Through transient photocurrent response, galvanostatic charge/discharge and electrochemical impedance measurements, it was established that cation-intercalation phenomena were principally responsible for charge-accumulation in the composite and that the incorporation of ionic species into interstitial surface sites was more energetically favourable for protons than for sodium ions. The composite displayed promising capacitive performance in the tested electrolytes, exhibiting Coulombic efficiencies of up to 88% under galvanostatic cycling at 1.0 mA cm&lt;sup&gt;-2&lt;/sup&gt; alongside a peak differential capacitance value of 560 mF cm&lt;sup&gt;-2&lt;/sup&gt; during the discharge phase. From electrochemical impedance spectroscopy data it was further determined that whilst illumination by white light acted to decrease the series resistance of the photoanode, all other resistive and capacitive components of the impedance characteristics were affected negligibly by the irradiation. In combination, the investigations detailed herein provide an instructive resource for the development of CdS/WO&lt;sub&gt;x&lt;/sub&gt; composites and the optimisation of electrolytes to improve the performance and chemical stability of such materials. Furthermore, the study serves as a potential foundation from which to advance the concept of integrating the conversion and storage of solar energy into a single dual-functional electrode, in turn facilitating a new generation of photo-supercapacitor devices.&lt;/p&gt; Pseudocapacitance ; Dielectric spectroscopy ; Electrolyte ; Materials science ; Electrochemistry ; Aqueous solution ; Nanocomposite ; Inorganic chemistry ; Chemical engineering ; Supercapacitor ; Chemistry ; Nanotechnology ; Electrode Transition Metal Oxide Nanomaterials ; Chalcogenide Semiconductor Thin Films ; Gas Sensing Nanomaterials and Sensors
Authors: Russell Keanini | Jerry Dahlberg | Peter Tkacik
Source: Scientific Reports (preprint, 2021-01-28)
Field: Materials Science — Materials Chemistry

On the physical mechanisms underlying single molecule dynamics in simple liquids Physical arguments and comparisons with published experimental data suggest that in simple liquids: (i) single-molecule-scale viscous forces are produced by temperature-dependent London dispersion forces, (ii) viscosity decay with increasing temperature reflects electron cloud compression and attendant suppression of electron screening, produced by increased nuclear agitation, and (iii) temperature-dependent self-diffusion is driven by a narrow band of phonon frequencies lying at the low-frequency end of the solid-state-like phonon spectrum. The results suggest that collision-induced electron cloud distortion plays a decisive role in single molecule dynamics: (i) electron cloud compression produces short-lived repulsive states and single molecule, self-diffusive hops, while (ii) shear-induced distortion generates viscosity and single-molecule-scale viscous drag. The results provide new insight into nonequilibrium molecular dynamics in nonpolar, nonmetallic liquids. Viscosity ; Drag ; Molecule ; Distortion (music) ; Non-equilibrium thermodynamics ; Phonon ; Electron ; Dispersion (optics) ; Diffusion ; Chemical physics ; Chemistry ; Materials science ; Condensed matter physics ; Molecular physics ; Physics ; Thermodynamics ; Quantum mechanics ; Amplifier Material Dynamics and Properties ; Quantum, superfluid, helium dynamics ; Spectroscopy and Quantum Chemical Studies
Authors: Erik Hartman | Simon Mahdavi | Sven Kjellström | Artur Schmidtchen
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2021-05-20)
Field: Chemistry — Spectroscopy

Peptimetric: Quantifying and visualizing differences in peptidomic data Abstract Finding new sustainable means of diagnosing and treating diseases is one of the most pressing issues of our time. In recent years, several endogenous peptides have been found to be both excellent biomarkers for many diseases and to possess important physiological roles which may be utilized in treatments. The detection of peptides has been facilitated by the rapid development of biological mass spectrometry and now the combination of fast and sensitive high resolution MS instruments and stable nano HP-LC equipment sequences thousands of peptides in one single experiment. In most research conducted with these advanced systems, proteolytically cleaved proteins are analyzed and the specific peptides are identified by software dedicated for protein quantification using different proteomics workflows. Analysis of endogenous peptides with peptidomics workflows also benefit from the novel sensitive and advanced instrumentation, however, the generated peptidomic data is vast and subsequently laborious to visualize and examine, creating a bottleneck in the analysis. Therefore, we have created Peptimetric, an application designed to allow researchers to investigate and discover differences between peptidomic samples. Peptimetric allows the user to dynamically and interactively investigate the proteins, peptides, and some general characteristics of multiple samples, and is available as a web application at https://peptimetric.herokuapp.com . To illustrate the utility of Peptimetric, we’ve applied it to a peptidomic dataset of 15 urine samples from diabetic patients and corresponding data from healthy subjects. Workflow ; Bottleneck ; Computer science ; Computational biology ; Software ; Proteomics ; Instrumentation (computer programming) ; Data mining ; Bioinformatics ; Data science ; Biology ; Database ; Embedded system Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Machine Learning in Bioinformatics
Authors: Sergio Mena | Solène Dietsch | Shane N. Berger | Colby E. Witt | Parastoo Hashemi
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2021-04-09)
Field: Chemistry — Electrochemistry

Novel, User-friendly Experimental and Analysis Strategies for Fast Voltammetry: 1. “The Analysis Kid” for FSCV ABSTRACT Fast-scan cyclic voltammetry at carbon fiber microelectrodes measures low concentrations of analytes in biological systems. There are ongoing efforts to simplify FSCV analysis and several custom platforms are available for filtering and multi-modal analysis of FSCV signals but there is no single, easily accessible platform that has capacity for all these features. Here we present The Analysis Kid : a free, open-source cloud application that does not require a specialized runtime environment and is easily accessible via common browsers. We show that a user-friendly interface can analyze multi-platform file formats to provide multimodal visualization of FSCV color plots with digital background subtraction. We highlight key features that allow interactive calibration and parametric analysis via peak finding algorithms to automatically detect the maximum amplitude, area under the curve and clearance rate of the signal. Finally, The Analysis Kid enables semi-automatic fitting of data with Michaelis Menten kinetics with single or dual reuptake models. The Analysis Kid can be freely accessed at https://analysis-kid.herokuapp.com/ . The web application code is found, under an MIT license, at https://github.com/sermeor/The-Analysis-Kid . Computer science ; Interface (matter) ; Visualization ; Artificial intelligence ; Operating system Electrochemical Analysis and Applications ; Analytical Chemistry and Sensors ; Electrochemical sensors and biosensors
Authors: Benedikt B. Straub | Henrik Schmidt | Peyman Rostami | Franziska Henrich | Massimiliano Rossi | Christian J. Kähler | Hans‐Jürgen Butt | Günter K. Auernhammer
Source: Soft Matter (preprint, 2021-01-01)
Field: Materials Science — Surfaces, Coatings and Films

Flow profiles near receding three-phase contact lines: influence of surfactants The dynamics of wetting and dewetting is largely determined by the velocity field near the contact lines. For water drops it has been observed that adding surfactant decreases the dynamic receding contact angle even at a concentration much lower than the critical micelle concentration (CMC). To better understand why surfactants have such a drastic effect on drop dynamics, we constructed a dedicated setup on an inverted microscope, in which an aqueous drop is held stationary while the transparent substrate is moved horizontally. Using astigmatism particle tracking velocimetry, we track the 3D displacement of the tracer particles in the flow. We study how surfactants alter the flow dynamics near the receding contact line of a moving drop for capillary numbers in the order of 10<sup>-6</sup>. Even for surfactant concentrations <i>c</i> far below the critical micelle concentration (<i>c</i> ≪ CMC) Marangoni stresses change the flow drastically. We discuss our results first in a 2D model that considers advective and diffusive surfactant transport and deduce estimates of the magnitude and scaling of the Marangoni stress from this. Modeling and experiment agree that a tiny gradient in surface tension of a few μN m<sup>-1</sup> is enough to alter the flow profile significantly. The variation of the Marangoni stress with the distance from the contact line suggests that the 2D advection-diffusion model has to be extended to a full 3D model. The effect is ubiquitous, since surfactant is present in many technical and natural dewetting processes either deliberately or as contamination. Marangoni effect ; Dewetting ; Contact angle ; Pulmonary surfactant ; Wetting ; Surface tension ; Drop (telecommunication) ; Particle tracking velocimetry ; Materials science ; Velocimetry ; Optics ; Mechanics ; Capillary action ; Flow (mathematics) ; Particle image velocimetry ; Physics ; Thermodynamics ; Composite material ; Mechanical engineering Surface Modification and Superhydrophobicity ; Fluid Dynamics and Thin Films ; Fluid Dynamics and Heat Transfer
Authors: M S Nagar | Walid Mohamed Morsy | Mustafa Bayoumi | Ahamed S. Shalan
Source: Research Square (preprint, 2021-07-13)
Field: Chemistry — Inorganic Chemistry

Potentiality of caro’s acid in leaching of uranium and radioactive measurements from Abu-Rusheid mylonitic gneiss rocks, South Eastern Desert, Egypt Abstract Abu Rusheid area is located at the Southern Eastern Desert of Egypt and composed of Mylonitic gneiss rocks (mineralized rock), Serpentinite rocks, Ophiolitic metagabbro, Ophiolitic mélange, Monzogranites, post- granitic dykes (lamprophyre and dolerite), veins and recent alluvial deposits. This paper is concerned with the study of potentiality of sulphuric and caro’s acid in uranium dissolution from Abu Rusheid mineralized rocks. For this purpose, many batch dissolution experiments were conducted. The obtained results showed that 91.5% and 52% uranium leachability for Caro’s acid and dilute sulfuric acid respectively. The reaction mechanism was described using shrinking core models. Gneiss ; Geology ; Geochemistry ; Uranium ; Mylonite ; Leaching (pedology) ; Dissolution ; Metamorphic rock ; Metallurgy ; Chemistry ; Tectonics Radioactive element chemistry and processing ; Geochemistry and Geologic Mapping ; Hydrocarbon exploration and reservoir analysis
Authors: Manafov MR
Source: Research & Development in Material Science (article, 2021-04-30)
Field: Materials Science — Polymers and Plastics

Modeling the Wax Deposition Process and Diffusion Kinetics of Wax Crystallization Problems related to crystallization and deposition of paraffin and asphalt-resinous substances from oil in transport pipes are considered. It is noted that the deposition of paraffin particles is of a migrationdiffusion nature. The migration -diffusion mechanism and kinetics of paraffin crystallization and their deposits in transport and heat exchangers pipes are proposed. To solve the heat transfer equation, a model of temperature distribution in pipes with deposits is proposed. Comparison of the models with the existing experimental data gave satisfactory results. At the same time, modern software tools for modeling the wax deposition process are considered. It is noted that the simulation results are not always applicable to real field cases. A scaling effect is needed for a more reliable interpretation. Wax ; Crystallization ; Kinetics ; Diffusion ; Chemical engineering ; Deposition (geology) ; Chemistry ; Materials science ; Thermodynamics ; Organic chemistry ; Engineering ; Geology ; Physics Textile materials and evaluations ; Material Properties and Processing
Authors: Akiko N. Itakura | Naoya Miyauchi | Yoshiharu Murase | Taro Yakabe | Masahiro Kitajima | Satoka Aoyagi
Source: Institutional Repositories DataBase (IRDB) (article, 2021-04-20)
Field: Materials Science — Metals and Alloys

Model of local hydrogen permeability in stainless steel with two&nbsp;coexisting structures Permeability (electromagnetism) ; Welding ; Austenitic stainless steel ; Work (physics) ; Weldability ; Hydrogen embrittlement Hydrogen embrittlement and corrosion behaviors in metals ; Material Properties and Failure Mechanisms ; Fusion materials and technologies
Authors: М. А. Ryabikina | Олександр Петрович Чейлях | O.S. Maksymyshyna
Source: Reporter of the Priazovskyi State Technical University Section Technical sciences (article, 2021-01-01)
Field: Materials Science — General Materials Science

Influence of carburizing and HFC quench-ing on characteristics of diffusion layer of 25CrMnTi steel This article considers the structure and properties of carburized coatings on 25CrMnTi steel, obtained by surface hardening methods, namely, gas carburizing, HFC quenching from temperatures of 800-1000°С&nbsp;and tempering at 200°С. The features of the structure of the diffusion layer have been studied; it has been shown that for all variants of thermal hardening, the microstructure of 25CrMnTi steel is a mixture of martensite, retained austenite and carbides (M +Aret.+ C). With the quenching temperature increase structureless martensite in the surface layer is replaced by acicular martensite. The maximum amount of retained austenite (≈40%) is observed at quenching temperatures of 800 and 1000°С; the core structure being low-carbon martensite. It has been established that the optimum properties, that is surface microhardness 870 HV and relative wear resistance coefficient&nbsp;ε&nbsp;= 1,5 – were obtained by HFC quenching from 1000ºС&nbsp;and, possibly, are due to the subsequent deformation transformation of retained austenite into martensite. Hardness and wear tests are presented in graphical form, results have been discussed and conclusions have been drawn. Through the use of the Fick's equation and the error function erf(t), the calculated concentration of carbon in the depth of the steel layer 25CrMnTi after cementation in the range of 820-960°C has been determined. When modelling gas cementation under the conditions of the machine building enterprise «MAGMA», Mariupol: t = 950°C,&nbsp;τ&nbsp;= 12 hours on the surface of the diffusion layer, the estimated carbon concentration reaches 1.2%, equal to the initial concentration of 0.25 % at a total case depth (TCD) = 1.75 mm. During cementation, the effective case depth&nbsp;(ECD) is usually controlled at 0.45% C (HRC50) – ECD = 1.25 mm. Increasing the ECD increases the strength, surface durability of gears and the service life of the transmission system as a whole; but on the contrary, too deep carburization depth can result in reduced gearing strength due to different ECD of external and internal gears, and greater complexity of the technological cycle. The calculated parameters of TCD and ECD correlate with the experimental curves of the microhardness of steel 25CrMnTi from the depth of the layer Carburizing ; Martensite ; Materials science ; Austenite ; Quenching (fluorescence) ; Metallurgy ; Tempering ; Hardening (computing) ; Carbide ; Hardness ; Surface layer ; Microstructure ; Layer (electronics) ; Composite material Material Properties and Applications ; Surface Treatment and Coatings ; Metal Alloys Wear and Properties