jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: S. V. Petrenko | Karen Page
Source: arXiv (Cornell University) (preprint, 2024-05-14)
Field: Materials Science — Biomaterials

Modelling the Impact of Organic Molecules and Phosphate Ions on Biosilica Pattern Formation in Diatoms The rapid and complex patterning of biosilica in diatom frustules is of great interest in nanotechnology, although it remains incompletely understood. Specific organic molecules, including long-chain polyamines, silaffins, and silacidins are essential in this process. The molecular structure of the synthesized polyamines significantly affects the quantity, size, and shape of silica precipitates. Experimental findings show that silica precipitation occurs at specific phosphate ion concentrations. We focus on the hypothesis that pattern formation in diatom valve structures is driven by phase separation of species-specific organic molecules. The resulting organic structures serve as templates for silica precipitation. We investigate the role of phosphate ions in self-assembly of organic molecules and analyze how the reaction between them affects the morphology of the organic template. Using mathematical and computational techniques, we gain an understanding of the range of patterns that can arise in a phase-separating system. By varying the degree of dissociation and the initial concentrations of reacting components we demonstrate that the resulting geometric features are highly dependent on these factors. This approach provides insights into the parameters controlling patterning. Additionally, we consider the effects of prepatterns, mimicking silica ribs that preexist the pores, on the final patterns. Phosphate ; Ion ; Chemistry ; Organic molecules ; Molecule ; Environmental chemistry ; Biochemistry ; Organic chemistry Diatoms and Algae Research
Source: Materials International (article, 2024-06-10)
Field: Materials Science — Biomaterials

Pecan Shells and Pecan Shell Activated Carbons as Sorbents to Remove Pollutants from Aqueous Media (a Literature Review) This review summarizes the literature data on the use of pecan (Carya illinoinensis) shells as sorption materials to remove ions of various metals (Cr(III) and Cr(VI), Cu2+, Fe3+, Mn(II), Pb2+ and Zn2+), dyes, and some organic compounds from aqueous media. Brief details are given regarding the quantity of pecan shells produced, chemical makeup, physical and chemical characteristics, and methods for reuse in different sectors. The paper provides some adsorption parameters of the pollutants in question. It was found that the Langmuir and Freundlich models, in most cases, accurately describe the pollutant adsorption isotherms, and the processes' kinetics correspond to the pseudo-second-order model. It has been shown that pecan shells are a good precursor for activated carbon production, which can also be used to remove various pollutants from the aquatic medium. Pollutant ; Adsorption ; Sorption ; Activated carbon ; Aqueous solution ; Langmuir ; Freundlich equation ; Environmental chemistry ; Aqueous medium ; Shell (structure) ; Chemistry ; Environmental science ; Chemical engineering ; Materials science ; Organic chemistry ; Composite material Diatoms and Algae Research
Authors: Frank Cichos | T. Xia | Haw Yang | Peter Zijlstra
Source: The Journal of Chemical Physics (article, 2024-07-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

The ever-expanding optics of single-molecules and nanoparticles Nanoparticle ; Nanotechnology ; Molecule ; Optics ; Materials science ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Quantum Dots Synthesis And Properties
Authors: Ashok A. Deniz
Source: Biophysical Journal (article, 2024-11-20)
Field: Chemistry — Physical and Theoretical Chemistry

Aging of biomolecular condensates reveals complexity—Through diffusion dynamics Diffusion ; Dynamics (music) ; Statistical physics ; Chemical physics ; Biological system ; Nanotechnology ; Physics ; Chemistry ; Materials science ; Biology ; Thermodynamics thermodynamics and calorimetric analyses ; Protein Structure and Dynamics
Authors: Suchada Sawasdee | Prachart Watcharabundit
Source: Applied Environmental Research (article, 2024-09-16)
Field: Chemistry — Inorganic Chemistry

Adsorption Behavior and Mechanism of Brilliant Green Dye onto Acid-modified Mesoporous Volcanic Pumice Water pollution is a major problem in the environment. The important one is the dying effluent from the textile industry. Dye effluent has affected human health and aquatic life. Recently, natural adsorbents have been most commonly used for dye treatment wastewater. This study explores the adsorption mechanism of brilliant green onto HCl-modified pumice. It involves a comparative analysis of the raw and HCl-modified pumice's characterization and adsorption properties. The adsorption experiments were carried out by considering several parameters, such as pH, contact time, initial dye concentrations, and temperatures. The research indicated that the raw and acid-treated pumice possess Si-OH and Si-O-Si groups. These pumice adsorbents are classified as mesoporous, exhibiting BJH pore diameters of 3.23 nm for the raw form and 3.69 nm for the acid-modified variant. The adsorption data revealed that the uptake of brilliant green dye was maximal at a pH of 8. The equilibrium results closely matched the Langmuir isotherm model. The maximum adsorption capacities were 37.13, 40.17, and 42.73 mg g-1 for the raw pumice, and 46.72, 51.81, and 56.17 mg g-1 for the modified pumice at 20, 30, and 40 °C, respectively. Furthermore, the removal efficiency of brilliant green dye with modified pumice was 91.93%, 95.29%, and 96.27% at 20°C, 30°C, and 40°C, respectively. The pseudo-second-order model was the most suitable for elucidating the kinetic adsorption data. The thermodynamic analysis revealed that the adsorption process was endothermic, spontaneous, and physical. Dipole-dipole H-bonding interaction, Yoshida H-bonding, electrostatic interaction, n-𝝅 interaction, cation exchange, and pore filling were all engaged in its process. Consequently, the local pumice volcanic rock became a great, cheap, abundant, and environmentally friendly adsorbent for removing dyes from effluents. Pumice ; Adsorption ; Mesoporous material ; Volcano ; Chemical engineering ; Brilliant green ; Materials science ; Chemistry ; Geology ; Geochemistry ; Organic chemistry ; Engineering ; Catalysis Pigment Synthesis and Properties
Authors: Charitha Thambiliyagodage | Himasha Gunathilaka
Source: Preprints.org (preprint, 2024-09-30)
Field: Chemistry — Organic Chemistry

Adsorptive Removal of Methylene Blue by Fe3O4/Fe2TiO5/TiO2 Nanocomposite Fabricated from Natural Ilmenite Sand A novel nanomaterial was synthesized using natural ilmenite sand via a simple precipitation method, and its ability to remove dyes in wastewater was evaluated using methylene blue (MB). The nanomaterial was synthesized by neutralizing the acid leachate obtained by Ilmenite sand digestion, followed by drying at 180 °C. It was characterized by X-ray diffractometry, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray fluorescence spectroscopy, and Brunauer, Emmett, and Teller surface area analyzer. Synthesized nanoparticles are a composite of Fe3O4/Fe2TiO5/TiO2 with a surface area of 292.18 m2/g pore size distribution with an average pore size of 1.53 nm and pore volume of 0.202 cc/g. The maximum adsorption capacity of 24.573 mg/g was obtained at pH 10 for 10 mg of the nanomaterial used with 10 mg/L MB. Dye concentration was varied in the range of 10-25 mg/L with 5 mg/L increment where equilibrium adsorption capacities of 24.573, 31.012, 41.443, and 52.259 mg/g were obtained with 10, 15, 20, and 25 mg/L, respectively. The adsorbent dosage varied as 10, 25, 45, 65, and 100 mg, and the highest adsorbent capacity of 24.573 mg/g was obtained with 10 mg of the adsorbent and 10 mg/L MB. Adsorption of MB followed pseudo-second-order kinetics with an adsorption capacity of 24.863 mg/g. The intraparticle diffusion model revealed that the MB adsorb in three different stages, and corresponding intra-particle diffusion constants of 1.50, 2.71, 3.38, and 4.41 g/mg min1/2 were calculated with the above dye concentrations. Adsorption followed the Langmuir isotherm model. Thermodynamics parameters ΔG, ΔH, and ΔS were calculated to be -27.5521 kJ/mol at 298 K, 2.571 kJ/mol, and 0.101 kJ/mol, respectively, in the experiments carried out varying the temperature. Regeneration studies of the adsorbent were carried out for five cycles, indicating some activity loss after each cycle. Ilmenite ; Methylene blue ; Nanocomposite ; Materials science ; Chemical engineering ; Nuclear chemistry ; Chemistry ; Mineralogy ; Nanotechnology ; Photocatalysis ; Organic chemistry ; Catalysis ; Engineering Nanomaterials for catalytic reactions
Authors: A. Dorathy Cathrine
Source: Communications on Applied Nonlinear Analysis (article, 2024-12-23)
Field: Chemistry — Organic Chemistry

Theoretical Analysis of Nonlinear Reaction-diffusion Equation on Immobilised Alpha-Chymotrypsin in Acetonitrile Solvent The study focuses on immobilised Alpha-chymotrypsin operating under kinetic constraints. This model incorporates equations representing the inherent kinetics of four distinct reactions, along with the experimentally analysed physical properties of three different support materials, to estimate the immobilised biocatalyst's initial activity and nucleophile selectivity. Approximate analytical solutions of acyl donor and nucleophile substrate concentrations under steady-state conditions are derived concerning all diffusion parameters using Akbari Ganji and homotopy perturbation methods. We examine our analytical results with numerical data obtained using MATLAB software to assess accuracy. It is shown that the derived analytical results closely match the numerical results. The model reliably replicates experimentally observed trends in initial rate and nucleophile selectivity across varying enzyme loadings. Alpha-chymotrypsin ; Acetonitrile ; Alpha (finance) ; Solvent ; Chemistry ; Diffusion ; Nonlinear system ; Chymotrypsin ; Chromatography ; Thermodynamics ; Organic chemistry ; Enzyme ; Physics ; Mathematics ; Trypsin ; Statistics Surfactants and Colloidal Systems
Authors: Ahmad Hassan | Emad A. S. Al-Hyali
Source: Maǧallaẗ abḥāṯ kulliyyaẗ al-tarbiyaẗ al-asāsiyyaẗ/Mağallaẗ abḥāṯ kulliyyaẗ al-tarbiyaẗ al-asāsiyyaẗ (article, 2024-06-01)
Field: Chemistry — Spectroscopy

Equilibrium, thermodynamic and kinetic studies of adsorption of Vitavax on carbon prepared from stems of Eucalyptus trees. This research included the preparation of a new type of activated carbon using the stems of eucalyptus trees obtained from the forests of the city of Mosul.It was found that this type of prepared carbon is of the nano type whose particle size is less than (100 nm), as its particle sizes ranged from (41.11, 58.64, 65.27 nm).This type of carbon was used to remove Vitavax pesticide, (in which the active substance is the carboxine) from its aqueous solutions.This research included the application of the Freundlich and Langmuir isotherms, and the results showed that the practical data of the system under study follows more of the Langmuir isotherms.This is indicated by the high (R) values, where the R value of Freundlich was (0.9825), while the Langmuir value of R was (0.991).The thermodynamic study of adsorption in the system under consideration showed that it is a spontaneous process through (negative G o ) values and leads to greater uniformity after the adsorption process, in addition to the force that controls the bond between the pesticide and the carbon surface, are physical forces (H = -8.558).The research also included the application of four kinetic models on the practical data of the system under study, namely, pseudo-first-order, pseudo-second-order, and intra particle diffusion.The results showed that the adsorption system used in this research follows the pseudo second-order reaction equation, and that the process of intra particle molecular diffusion is not the only mechanism that dominates the adsorption process. Adsorption ; Carbon fibers ; Kinetic energy ; Eucalyptus ; Degradation (telecommunications) Adsorption, diffusion, and thermodynamic properties of materials
Authors: Manuel Dedola | Gaia Cassarà-Airoldi | Ludovico Cademartiri
Source: arXiv (Cornell University) (preprint, 2024-07-27)
Field: Chemistry — Physical and Theoretical Chemistry

On The Effect Of Size On The Kinetics Of Reactions In Solutions Reactions in solution require "contact" between the reagents. We can predict the rate at which reagents come into "contact" (at least in dilute conditions), but if the initial collision does not lead to reaction, what happens then? The collision rates in solution-phase reactions are generally described (explicitly or implicitly) with the Smoluchowski equation. Unfortunately, that model describes coagulations in gases, not reactions in solutions. The model is memory-less, i.e., collisions are treated as random processes, unaware of each other in space and time. The reality is that unreactive collisions create memory: particles (even molecules) "remember" they just collided, i.e, the probability of collision depends on how far back in time their prior collision happened. As we show here, this purely geometric and statistical fact is valid as long as their size is larger than the Kuhn length of their Brownian motion in solution. Under these conditions, particles in solution form, even in the absence of attractive interactions, relatively long-lived "clusters" kept together by the statistical unlikeliness of separating. We show here through Brownian dynamics simulations that, as a result of this memory, the collision rates and the lifetimes of these clusters, differently from what predicted by Smoluchowski's model, are proportional to the ratio between the radius of the colliders and the Kuhn length of their path in solution, with a coefficient close to unity! Kinetics ; Chemistry ; Mathematics ; Thermodynamics ; Physics ; Classical mechanics Advanced Physical and Chemical Molecular Interactions ; Origins and Evolution of Life ; Advanced Thermodynamics and Statistical Mechanics
Authors: Amjed Sabah Kamil Janabi | Hayder M. Abdul‐Hameed
Source: International Journal of Design & Nature and Ecodynamics (article, 2024-02-28)
Field: Materials Science — Materials Chemistry

Revolutionizing Water Hyacinth Flash Graphene Technology to Remove Cu(II) from Wastewater: Equilibrium Isotherm, Kinetics and Thermodynamic Studies Hyacinth ; Wastewater ; Kinetics ; Flash (photography) ; Graphene ; Thermodynamics ; Thermodynamic equilibrium ; Chemistry ; Materials science ; Environmental science ; Chemical engineering ; Environmental engineering ; Nanotechnology ; Physics ; Engineering ; Organic chemistry Graphene research and applications ; Adsorption and biosorption for pollutant removal ; Nanomaterials for catalytic reactions
Authors: Ruben Goldhahn | Ann-Joelle Minor | Liisa Rihko‐Struckmann | Siew‐Wan Ohl | Patricia Pfeiffer | Claus‐Dieter Ohl | Kai Sundmacher
Source: ChemRxiv (preprint, 2024-07-01)
Field: Materials Science — Polymers and Plastics

Recycling of Bulk Polyamide 6 by Dissolution- Precipitation in CaCl2-EtOH-H2O Mixtures Given the problems of virgin plastic production from fossil resources and the growing amount of plastic waste, a rapid transition towards a circular economy is pursued. For recycling, the separation of mixed plastics into pure fractions is of paramount importance to prevent downcycling. Here, experimental parameters for selective bulk dissolution of polyamide 6 (PA 6) filaments (1.75 mm diameter, 1 cm long) using CaCl2-EtOH-H2O mixtures (CEW) at 75 ◦C are investigated. They include the energy supply mode, dissolution time, CEW composition and the CEW:PA mass ratio. Energy supply with ultrasound instead of microwaves improved the yield of dissolved and recovered PA 6 after 5 hours from 31 to 52%. In total, the PA 6 yield after 3 hours of bulk dissolution could be increased from 18 to 69% by changing the energy supply mode from microwave to ultrasound and the H2O:EtOH molar ratio of CEW from 0.40 to 1.33 whilst maintaining an optimal CEW:PA mass ratio of 8.5. Additionally, master plot analysis suggests that dissolution by microwave energy supply follows a contracting cylinder model, while ultrasonic energy supply aligns with a 2D diffusion or third-order kinetic model. Microscopic observations suggest that, in the case of ultrasonic energy supply, oscillating bubbles on the particle surface enhance the dissolution rate of PA 6 filaments in CEW. Polyamide ; Dissolution ; Precipitation ; Chemical engineering ; Chemistry ; Environmental science ; Materials science ; Composite material ; Meteorology ; Engineering ; Physics Polymer Science and PVC ; biodegradable polymer synthesis and properties ; Recycling and Waste Management Techniques
Authors: Zahraa Kamaz | Haruna Isiyaku Umar | Parth Doshi | Praveenya Suri
Source: Microbiology Research Journal International (article, 2024-04-05)
Field: Chemistry — Organic Chemistry

Glycosylated Antibiotics: New Promising Bacterial Efflux Pumps Inhibitors Antimicrobial resistance is considered a major concern problem; bacteria have evolved mechanisms to overcome antibiotics’ action through evolutionary process. One main resistance mechanism that bacteria developed is the pumping of the antibiotics out of bacterial cells by transmembrane transporter proteins known as efflux pumps. To overcome bacterial resistance guided by efflux pumps, efflux pumps inhibitors (EPIs) are small molecules that obstruct efflux pumps binding sites and its structural assembly leading to disability in the efflux pumps normal function, new EPIs which under the current study are created by modifying the chemical structure of most common antibiotics including Ampicillin, Penicillin, Chloramphenicol, Ciprofloxacin and Tetracycline, such antibiotics are modified by adding N-acetyl glucose amine moiety to acceptor OH group of the respective antibiotic, the newly modified antibiotics are glycosylated EPIs. To test the effectiveness of the new EPIs in inhibiting AcrB-TolC and MexA-OprM efflux pumps functions, ADME properties for all of glycosylated antibiotics have been measured through applying Lipinski’s role of 5, docking and simulation studies have been included as well. Docked glycosylated tetracycline has given the highest binding energy in the active sites of both pumps, with -9.4 against AcrB and -8.8 against MexA. The simulation study has confirmed the binding of the glycosylated tetracycline in the active sites of both pumps, as well as its stability during the biological dynamicity of both pumps (opening and closing channels). The results validation requires a long simulation time about 50 ns or more which was un applicable due to cost limitation, however, the newly glycosylated antibiotics have promising results that might make it eligible as drug candidates to overcome bacterial resistance. Efflux ; Antibiotics ; Microbiology ; Chemistry ; Pharmacology ; Medicine ; Biology ; Biochemistry Synthesis of β-Lactam Compounds ; Carbohydrate Chemistry and Synthesis ; Chemical Synthesis and Analysis
Authors: Sharifah Norain Mohd Sharif | Norhayati Hashim | Illyas Md Isa | Maizatul Najwa Jajuli | Afif Arifin | Norlaili Abu Bakar | Mazidah Mamat | Suyanta Suyanta
Source: Indonesian Journal of Chemistry (article, 2024-04-01)
Field: Materials Science — Materials Chemistry

Tween–80 Coating in Enhancing Physicochemical Stability, Kinetics and Release Mechanism of Layered Double Hydroxide-Ferulate This study aims to enhance the targeted delivery of a powerful antioxidant, ferulate (FA), by developing a controlled release formulation (CRF) based on the incorporation of layered double hydroxide and Tween-80 polymeric surfactant. The layered double hydroxide-ferulate (LDH-FA) synthesized by co-precipitation method was homogenously mixed with the Tween-80 coater under continuous stirring. The successful Tween-80 coating was verified with PXRD analysis and supported by FTIR. No changes in interlayer distance between LDH-FA (at 17.4 and 8.7 Å) and LDH-FA-T80 (at 17.6 and 8.6 Å) were observed in the PXRD pattern. TGA/DTG analysis demonstrated good thermal stability of LDH-FA-T80, with the ability to withstand extreme temperatures up to 460 °C. The association of Tween-80 with LDH-FA progressively sustained the release time of FA in each aqueous solution, with a release time of up to 440 min. For both LDH-FA and LDH-FA-T80, the release of FA is through dissolution and anion exchange release mechanism (regulated by pseudo-second-order kinetic model). The study's findings suggest practical applications of FA in the pharmaceutical industry by implying the retarding effect triggered by Tween-80, offering new insights for the application of CRF to enhance the therapeutic effect of FA. Kinetics ; Hydroxide ; Mechanism (biology) ; Chemical engineering ; Chemistry ; Coating ; Organic chemistry ; Physics ; Engineering Polyoxometalates: Synthesis and Applications ; Layered Double Hydroxides Synthesis and Applications ; Industrial Gas Emission Control
Authors: Suman Majumder | Subhajit Paul
Source: arXiv (Cornell University) (preprint, 2024-09-26)
Field: Materials Science — Polymers and Plastics

Anomalous Conformations and Dynamics of Active Block Copolymers Heterogeneous distribution of passive and active domains in the chromosome plays a crucial role for its dynamic organization within the cell nucleus. Motivated by that here we investigate the steady-state conformation and dynamics of a model active-block copolymer using numerical simulations. Our results show that depending on the relative arrangements of the active and passive blocks, the polymer shows an unusual swelling, even larger than the corresponding fully active polymer. On the one hand, the dynamics of the full polymer show usual enhanced diffusion and Rouse-like scaling behavior. On the other hand, individual passive and active blocks show anomalous transient super- and sub-diffusive dynamics. We characterize this anomalous dynamics in terms of the dependence of a generalized diffusion constant with the polymer length and activity strength. Copolymer ; Dynamics (music) ; Block (permutation group theory) ; Chemistry ; Physics ; Mathematics ; Polymer ; Geometry ; Organic chemistry Polymer Nanocomposites and Properties ; Advanced Polymer Synthesis and Characterization