jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zakir Hussain Shah | Najma Memon | Zeeshan Khatri | Kifayatullah Korejo | Muhammad Siddique Samoo | Abdul Majid Channa
Source: Mehran University Research Journal of Engineering and Technology (article, 2024-04-08)
Field: Materials Science — Biomaterials

Fabrication of electrospun ultrafine fibreous membrane and their application in paraben adsorption Electrospinning provides a simple and versatile method for generating ultrafine fibers from a rich variety of materials that include polymers, composites, and ceramics. Find applications in various fields, including tissue engineering, filter media, reinforcement in nanocomposites, and micro/nano-electro-mechanical systems. In this study the polystyrene fibers in 10%, 20% and 30% (w/v) in THF: DMF solvents were characterized by ATR-FTIR, AFM and SEM. The obtained fibers exhibited a smooth surface with fine structures, emphasizing a ribbon-like morphology with bead-like features within the range of 3 µm to 5 µm in diameter. The aim of this study was to extract the parabens at optimized conditions such as pH, adsorbent dose, contact time and the elution of solvent. To examine the mechanism of adsorption kinetics, the two most commonly used kinetics models (pseudo-first order and pseudo-second order) were employed to test experimental data along with the Morris-Weber diffusion model. The obtained data showed that the maximum sorption efficiency obtained at pH 3.0, adsorbent dose optimized as 10 mg of fiber with time of 24 hours, the methanol was sufficient to elute paraben from fibers met. The experimental data of the adsorption followed by first-order reaction with a mass transfer-controlled diffusion mechanism Adsorption ; Electrospinning ; Chemical engineering ; Materials science ; Polystyrene ; Paraben ; Solvent ; Mass transfer ; Nanocomposite ; Fiber ; Elution ; Polymer ; Diffusion ; Membrane ; Polymer chemistry ; Composite material ; Chemistry ; Chromatography ; Organic chemistry ; Preservative Electrospun Nanofibers in Biomedical Applications
Authors: Christine M. E. Kriebisch | Brigitte A. K. Kriebisch | Gregor Häfner | Yanyan Fei | Marcus Müller | Job Boekhoven
Source: ChemRxiv (preprint, 2024-10-06)
Field: Chemistry — Organic Chemistry

Chemically fueled active transport. Biology uses chemical potential differences from molecules like ATP to drive membrane pumps, transporting molecules across mem-branes even against concentration gradients. Here, we report a synthetic system that transports small molecules from an aqueous phase (the sender) to an aqueous receiver across a centimeter-sized immiscible solvent at the expense of chemical energy. Molecules with high chemical potential (fuels) in the sender phase transiently activate the transporter molecule to enter the immiscible solvent and exit on the receiver phase side, thus allowing transport from sender to receiver against a concentration gradient. Importantly, we show this active transport mechanism transports molecules across a hydrophobic barrier without complex pumping machinery. Using a reaction-diffusion model, we determined the critical parameters that determine the efficiency of the active transport. Selective transport enables the sorting of a mixture of different molecules. In future work, we will use these design criteria to actively transport molecules across membranes, e.g., of vesicles, at the expense of chemical fuel, thereby mimicking biological processes and enabling the feeding of synthetic cells. Environmental science ; Business Chemical Reaction Mechanisms
Authors: Xinyu Hou | Zongsheng Yue | Xiaoming Li | Chen Change Loy
Source: arXiv (Cornell University) (preprint, 2024-11-26)
Field: Chemistry — Organic Chemistry

Omegance: A Single Parameter for Various Granularities in Diffusion-Based Synthesis In this work, we introduce a single parameter $ω$, to effectively control granularity in diffusion-based synthesis. This parameter is incorporated during the denoising steps of the diffusion model's reverse process. Our approach does not require model retraining, architectural modifications, or additional computational overhead during inference, yet enables precise control over the level of details in the generated outputs. Moreover, spatial masks or denoising schedules with varying $ω$ values can be applied to achieve region-specific or timestep-specific granularity control. Prior knowledge of image composition from control signals or reference images further facilitates the creation of precise $ω$ masks for granularity control on specific objects. To highlight the parameter's role in controlling subtle detail variations, the technique is named Omegance, combining "omega" and "nuance". Our method demonstrates impressive performance across various image and video synthesis tasks and is adaptable to advanced diffusion models. The code is available at https://github.com/itsmag11/Omegance. Diffusion ; Computer science ; Algorithm ; Physics ; Thermodynamics Microwave-Assisted Synthesis and Applications
Authors: Karnamohit Ranka | Richard Kang | Prabhat Prakash | Soonho Kwon | Frances A. Houle | Martin Head‐Gordon | William A. Goddard
Source: ECS Meeting Abstracts (article, 2024-08-09)
Field: Materials Science — Materials Chemistry

Modeling Stochastic Kinetics of Cathodic Cu Surface Corrosion and Ionic Interaction in Nanoscopic Water Pools Cathodic Cu corrosion has been reported to occur in both the presence and absence of carbon dioxide in aqueous electrolytes and while the mechanism is not understood well it implies carbide-, hydride- and hydroxide-formation mediated pathways. Corrosion leads to roughening, which creates local pockets of electrolyte that are somewhat disconnected from the bulk. In this talk, we describe a combination of theoretical studies to identify reaction pathways, and kinetics modeling of them to obtain a working description of corrosion in water. Corrosion at metal surfaces is both influenced by and influences the formation of nanoscopic aqueous pools by trapping electrolyte solution in microscopic pockets. Such electrolyte nano-pools exhibit non-bulk behavior, and the lifetime of locally trapped ions can be significantly different than in the bulk. This can potentially have an effect on the chemistry in the local microenvironment. Stochastic reaction-diffusion models can be used to model kinetics of electrochemical processes at length and time scales relevant to laboratory experiments, allowing a direct comparison of transient observable quantities to time-resolved experimental data. Atomistic simulations employ methods of electronic structure theory (such as density functional theory (DFT)) and molecular dynamics (both classical and ab initio ) to describe a detailed picture of the (electro-)chemistry at microscopic time and length scales. Scaling up these methods to macroscopic levels is not trivial but required for direct comparison to experiment. By using Gibbs free energies obtained from atomistic simulations it is possible to calculate rate constants for individual elementary steps in reaction schemes describing kinetics of relevant processes. We use Kinetiscope to implement stochastic kinetics models of two reaction schemes describing: 1. cathodic Cu surface corrosion through formation of copper hydroxides, through which we aim to describe essential steps in the cathodic corrosion mechanism of metal surfaces; 2. interactions between bicarbonate and hydronium ions, both present in the bicarbonate salt buffers used routinely in electrochemical reduction at copper surfaces, in a nanoscopic water droplet to understand time-dependent changes in the local concentrations of electrolytes trapped at or near metal surfaces. Figure 1 Cathodic protection ; Nanoscopic scale ; Kinetics ; Corrosion ; Ionic bonding ; Materials science ; Metallurgy ; Chemical engineering ; Inorganic chemistry ; Chemistry ; Electrochemistry ; Nanotechnology ; Ion ; Electrode ; Physical chemistry ; Physics ; Engineering Corrosion Behavior and Inhibition ; Electrostatics and Colloid Interactions ; Water Treatment and Disinfection
Authors: Zhongyuan Liu | Qingbo Yu | Huaqing Xie | Jinchao Gao | Jiatai Zhao
Source: Processes (article, 2024-12-15)
Field: Materials Science — Materials Chemistry

Experimental and Kinetic Study of Biochar in N-Absorption Reaction of Chemical Looping Ammonia Generation The study conducted isothermal tests for biochar-based N-absorption reaction in Chemical Looping Ammonia Generation to investigate the factors affecting biochar conversion, the kinetic model, and the reaction mechanism. The results show that the N2 gas flows had little effect on biochar conversion. Raising the reaction temperature and the molar ratio of α-Al2O3 to C enhanced the conversion of biochar. When the N2 flow rate was set to 200 mL/min, the reaction temperature to 1600 °C, and the α-Al2O3/C molar ratio to 3:3, the biochar conversion reached its peak at 95.45%. After evaluating several kinetic models, the D1 diffusion model was found to provide the closest match to the biochar conversion. The activation energy decreased from 241.91 kJ/mol at a 1:3 α-Al2O3/C molar ratio to 146.77 kJ/mol at a 3:3 ratio with an increasing α-Al2O3/C molar ratio. The biochar’s high specific surface area and abundant pore structure facilitated a rapid reaction between carbon and oxygen on the carbon surface. Additionally, the diffusion of oxygen produced during the decomposition of α-Al2O3 became the limiting factor in the N-absorption reaction. Biochar ; Chemistry ; Diffusion ; Carbon fibers ; Absorption (acoustics) ; Oxygen ; Ammonia ; Inorganic chemistry ; Analytical Chemistry (journal) ; Chemical engineering ; Materials science ; Pyrolysis ; Chromatography ; Thermodynamics ; Organic chemistry Catalytic Processes in Materials Science ; Chemical Looping and Thermochemical Processes ; Ammonia Synthesis and Nitrogen Reduction
Authors: Moumita Chakraborty | Pradip Kumar Sadhu | Abhijit Kundu | Moumita Mukherjee
Source: Journal of Computational Electronics (article, 2024-08-04)
Field: Materials Science — Materials Chemistry

Strain engineered &lt; Si/Si0.97C0.03 &gt; superlattice photodetector for optoelectronic applications: a comprehensive numerical analysis and experimental verification Photodetector ; Responsivity ; Superlattice ; Quantum efficiency ; Optoelectronics ; Materials science ; Avalanche photodiode ; Quantum well infrared photodetector ; Wavelength ; Detector ; Quantum well ; Optics ; Physics Silicon Nanostructures and Photoluminescence ; Nanowire Synthesis and Applications ; Thin-Film Transistor Technologies
Authors: Jianyong Wei | Yumeng Liu | Yizhuo Wang | Kai Li | Zhentao Lian | Maosong Xie | Xinhan Yang | Seyed Saleh Mousavi Khaleghi | Fuxing Dai | Weida Hu | Xuejiao J. Gao | Rui Yang | Yaping Dan
Source: arXiv (Cornell University) (preprint, 2024-05-25)
Field: Materials Science — Materials Chemistry

Analytical photoresponses of Schottky contact MoS2 phototransistors High-gain photodetectors based on two-dimensional (2D) semiconductors, in particular those in photoconductive mode, have been extensively investigated in the past decade. However, the classical photoconductive theory was derived on two misplaced assumptions. In this work, we established an explicit analytical device model for Schottky contact MoS2 phototransistors that fits well with experimental data. From the fitting results, we found that the Richardson constant of the MoS2 Schottky contact is temperature dependent, indicating that the Schottky contacts for the 2D material is best described by the mixed thermionic emission and diffusion model. Based on this device model, we further established an analytical photoresponse for the few-layer MoS2 phototransistors, from which we found the voltage distribution on the two Schottky contacts and the channel, and extracted the minority carrier recombination lifetimes. The lifetimes are comparable with the values found from transient photoluminescence measurements, which therefore validates our analytical photoresponses for Schottky contact 2D semiconducting phototransistors. Materials science ; Optoelectronics ; Optics ; Physics 2D Materials and Applications ; Semiconductor materials and interfaces ; Chalcogenide Semiconductor Thin Films
Authors: G. Jayanthi | V. Andal | M. Prabaharan | Suba Kannaiyan
Source: Bulletin of the Chemical Society of Ethiopia (article, 2024-09-16)
Field: Chemistry — Organic Chemistry

TMAB modified NiFe2O4 nanoparticles for the Effective removal of Eriochrome Black-T azo dye The Eriochrome Black-T (EBT) azo dye was removed from aqueous solution using TMAB (tetramethyl ammonium bromide) stabilised NiFe2O4 (TMAB@NFO) nanoparticles, which have been synthesized through polymeric precursor method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectra (FTIR) were used to analyse the TMAB@NFO nanoparticles. Adsorption studies were conducted under a variety of conditions, including pH, adsorbent dosage, and contact time, intraparticle diffusion, pseudo-first- and pseudo-second-order kinetic models were used to analyse the kinetic data. According to the systematic study of adsorption isotherms and kinetics models, TMAB@NFO nanoparticles will adsorb EBT dye utilising the Freundlich model and pseudo-second-order kinetics. The intraparticle diffusion model revealed a linear relationship (R2 - 0.98, 0.97, and 0.94 for TMAB@NiFe2O4 and bare NiFe2O4-NPs), demonstrating how surface modification influences the overall EBT adsorption process and the pore diffusion rate. Additionally, the manufactured nano adsorbents of NiFe2O4 were effectively regenerated and reused after the treatments up to four times following the elimination of 89% of EBT dye by TMAB@NiFe2O4-NPs. The results have demonstrated the enormous potential of TMAB @NiFe2O4-NPs to eliminate EBT in a practical way. KEY WORDS: Tetramethyl ammonium bromide, NiFe2O4, EBT, Surface capping, Adsorption, Kinetics Bull. Chem. Soc. Ethiop. 2024, 38(6), 1569-1581. DOI: https://dx.doi.org/10.4314/bcse.v38i6.6 Chemistry ; Eriochrome Black T ; Nanoparticle ; Nuclear chemistry ; Chemical engineering ; Polymer chemistry ; Physical chemistry ; Adsorption Nanomaterials for catalytic reactions
Authors: Jiwei Li | Wentao Chen | Hui Huang | Siyu Yuan | Xichen Xu | Bingyang Cai | Ya Cui | Miao Zhang | Weimin Zhou | Jie Luo
Source: Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition (article, 2024-11-26)
Field: Materials Science — Materials Chemistry

Unsupervised MR2PET Synthesis Provides Pseudo-Normal Reference to Improve Epileptic Lesion Detection Motivation: It is challenging to obtain demographically matched controls for every patient who underwent FDG PET examinations. Goal(s): We aim to generate pseudo-normal PET for each epilepsy patient leveraging recent progress in cross modality image translation. Approach: We employed diffusion model to learn the translation between T1w-MRI and FDG PET of healthy subjects, then generated pseudo-normal PET for a cohort of 104 patients with focal epilepsy, who underwent PET/MR scanning for presurgical evaluation. Results: Unsupervised SynDiff achieved comparable performance as supervised Pix2pixGAN in PET synthesis. Improved DICE coefficient and lesion detection were achieved using synthesized reference compared with traditional group reference. Impact: Imaging translation provides a personalized pseudo-normal reference for each epilepsy patient. Pseudo-normal PET is poised for potential adoption as an auxiliary tool to enhance the capability of PET imaging in detecting epileptic lesions within clinical settings. Computer science ; Epilepsy ; Artificial intelligence ; Pattern recognition (psychology) ; Neuroscience ; Psychology Machine Learning in Materials Science
Authors: Haochen Wang | Jun Zhao
Source: Materials Today Communications (article, 2024-07-30)
Field: Materials Science — Polymers and Plastics

Characterization and optimization of waste Cucurbita maxima moschata lashes for biomass composite applications Cucurbita moschata ; Materials science ; Cucurbita maxima ; Biomass (ecology) ; Composite number ; Characterization (materials science) ; Maxima ; Botany ; Composite material ; Biology ; Nanotechnology ; Agronomy Natural Fiber Reinforced Composites ; Advanced Cellulose Research Studies ; Additive Manufacturing and 3D Printing Technologies
Authors: Anton Pfannstiel | Mirco Imlau | M. Bazzan | Laura Vittadello
Source: arXiv (Cornell University) (preprint, 2024-06-12)
Field: Materials Science — Materials Chemistry

Defect-related Anomalous Mobility of Small polarons in Oxides: the Case of Congruent Lithium Niobate Polarons play a major role in the description of optical, electrical and dielectrical properties of several ferroelectric oxides. The motion of those particles occur by elementary hops among the material lattice sites. In order to compute macroscopic transport parameters such as charge mobility, normal diffusion laws are generally assumed. In this paper we show that when defect states able to trap the polarons for long times are considered, significant deviations from the normal diffusion behaviour arise. As an example of this behavior, we consider here the case of lithium niobate (LN), a prototypical system, having interacting polaron types. Our analysis considers the case of a stoichiometric LN containing a certain concentration of small electron polarons hopping on regular Nb sites and compares it to the material in congruent composition, which is characterized by a large concentration of antisite defects. While in the first case the charge carriers are free polarons hopping on a regular Nb sublattice, in the second case a fraction of polarons is trapped on antisite defects. Thus a range of different hopping possibilities arises, depending on the type of starting and destination sites. We develop a formalism encompassing all these microscopic processes in the framework of a switching diffusion model which can be well approximated by a mobile-immobile transport model providing explicit expressions for the polaron mobility. Starting from the Marcus-Holstein model for the polaron hopping frequency we verify by means of a Monte Carlo approach the diffusion/mobility of the different polarons showing that, while free polarons obey the laws for normal diffusion as expected, bound polarons follow an anomalous diffusion behaviour and that in the case of the congruent crystal where mixed free and bound polaron transport is involved, our expressions indeed provide a satisfactory description. Polaron ; Lithium niobate ; Lithium (medication) ; Materials science ; Condensed matter physics ; Physics ; Optoelectronics ; Psychology ; Quantum mechanics ; Psychiatry Ferroelectric and Piezoelectric Materials ; Microwave Dielectric Ceramics Synthesis ; Nuclear materials and radiation effects
Authors: Л. В. Фомин | A. A. Dalinkevich | Yu. G. Basalov
Source: Mechanics of Solids (article, 2024-10-01)
Field: Materials Science — Materials Chemistry

On The Influence of a Non-Classical Diffusion Process on the Long-Term Fracture of a Composite Tensile Rod During Creep The stress-strain state is considered and the time to fracture of a composite tensile rod during creep in an active medium is determined. The influence of the active medium is determined by a non-classical diffusion process, with the active substance penetrating into the material in two states: free and bound. The process of such diffusion is described by a modified diffusion equation that takes into account the two-phase state of the active substance in the material. A system of equations has been obtained that models the creep of a composite rod, in which its parts are rigidly connected to each other without slipping, and also includes kinetic equations for the accumulation of damage in parts of the rod. The influence of the active medium is taken into account by introducing into the indicated kinetic equations the function of the influence of the active medium - a function of the integral average concentration. Stress distributions and damage accumulation processes over time in various parts of the composite rod are analyzed. Calculations were carried out in two cases, namely, classical and non-classical diffusion processes are considered. The setting of these differences is determined by the choice of appropriate parameters in the diffusion model under consideration. Dependences of damage accumulation and stress distribution in parts of the rod over time were obtained. As a result, it was determined that the destruction of a composite rod in the classical case occurs earlier than in the case of the considered non-classical diffusion process. Creep ; Materials science ; Composite number ; Term (time) ; Ultimate tensile strength ; Composite material ; Fracture (geology) ; Diffusion ; Diffusion process ; Process (computing) ; Thermodynamics ; Computer science ; Physics ; Innovation diffusion Material Properties and Failure Mechanisms ; Elasticity and Wave Propagation ; Polymer Science and Applications
Authors: Ahmadreza Riyahi khorasgani | Ingo Steinbach | Bettina Camin | Julia Kundin
Source: Research Square (preprint, 2024-11-26)
Field: Materials Science — Materials Chemistry

Morphological Instability of Kirkendall Voids: A Phase-Field Study Kirkendall effect ; Instability ; Field (mathematics) ; Phase (matter) ; Materials science ; Mechanics ; Metallurgy ; Mathematics ; Physics Solidification and crystal growth phenomena
Authors: Bartosz Barzdajn | Christopher Race
Source: arXiv (Cornell University) (preprint, 2024-05-06)
Field: Materials Science — Materials Chemistry

Molecular dynamics simulations of neutron induced collision cascades in Zr - statistical modelling of irradiation damage and potential applications Understanding the nature of irradiation damage often requires a multi-scale and multi-physics approach, i.e. it requires a significant amount of information from experiments, simulations and phenomenological models. This paper focuses on the initial stages of irradiation damage, namely neutron-induced displacement cascades in zirconium, as nuclear-grade zirconium alloys are widely used in fuel assemblies. We provide results of large-scale molecular dynamics (MD) simulations based on existing inter-atomic potentials and the two-temperature model to include the effect of electron-phonon coupling. Our data can be used directly in higher scale methods. Furthermore, we analysed summary statistics associated with defect production, such as the number of defects produced, their distribution and the size of clusters. As a result, we have developed a generative model of collision cascades. The model is hierarchical, as well as stochastic, i.e. it includes the variance of the considered features. This development had three main objectives: to establish a sufficient descriptor of a cascade, to develop an interpolator of data obtained from high-fidelity simulations, and to demonstrate that the statistical model of the data can generate representative distributions of primary irradiation defects. The results can be used to generate synthetic inputs for longer length- and time-scale models, as well as to build fast approximations relating dose, damage and irradiation conditions. Molecular dynamics ; Collision ; Dynamics (music) ; Nuclear physics ; Statistical physics ; Neutron ; Irradiation ; Nuclear engineering ; Materials science ; Physics ; Chemistry ; Computer science ; Computational chemistry ; Engineering Nuclear Materials and Properties ; Nuclear reactor physics and engineering ; Nuclear Physics and Applications