jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zijie Wu | Audrey M. Collins | Arthi Jayaraman
Source: Biomacromolecules (article, 2024-02-28)
Field: Materials Science — Biomaterials

Understanding Self-Assembly and Molecular Packing in Methylcellulose Aqueous Solutions Using Multiscale Modeling and Simulations We present a multiscale molecular dynamics (MD) simulation study on self-assembly in methylcellulose (MC) aqueous solutions. First, using MD simulations with a new coarse-grained (CG) model of MC chains in implicit water, we establish how the MC chains self-assemble to form fibrils and fibrillar networks and elucidate the MC chains' packing within the assembled fibrils. The CG model for MC is extended from a previously developed model for unsubstituted cellulose and captures the directionality of H-bonding interactions between the -OH groups. The choice and placement of the CG beads within each monomer facilitates explicit modeling of the exact degree and position of methoxy substitutions in the monomers along the MC chain. CG MD simulations show that with increasing hydrophobic effect and/or increasing H-bonding strength, the commercial MC chains (with degree of methoxy substitution, DS, ∼1.8) assemble from a random dispersed configuration into fibrils. The assembled fibrils exhibit consistent fibril diameters regardless of the molecular weight and concentration of MC chains, in agreement with past experiments. Most MC chains' axes are aligned with the fibril axis, and some MC chains exhibit twisted conformations in the fibril. To understand the molecular driving force for the twist, we conduct atomistic simulations of MC chains preassembled in fibrils (without any chain twists) in explicit water at 300 and 348 K. These atomistic simulations also show that at DS = 1.8, MC chains adopt twisted conformations, with these twists being more prominent at higher temperatures, likely as a result of shielding of hydrophobic methyl groups from water. For MC chains with varying DS, at 348 K, atomistic simulations show a nonmonotonic effect of DS on water-monomer contacts. For 0.0 < DS < 0.6, the MC monomers have more water contacts than at DS = 0.0 or DS > 0.6, suggesting that with few methoxy substitutions, the MC chains are effectively hydrophilic, letting the water molecules diffuse into the fibril to participate in H-bonds with the MC chains' remaining -OH groups. At DS > 0.6, the MC monomers become increasingly hydrophobic, as seen by decreasing water contacts around each monomer. We conclude based on the atomistic observations that MC chains with lower degrees of substitutions (DS ≤ 0.6) should exhibit solubility in water over broader temperature ranges than DS ∼ 1.8 chains. Aqueous solution ; Molecular dynamics ; Molecular model ; Self-assembly ; Chemical engineering ; Chemistry ; Materials science ; Polymer science ; Polymer chemistry ; Nanotechnology ; Computational chemistry ; Organic chemistry ; Engineering Advanced Cellulose Research Studies ; Surfactants and Colloidal Systems ; Polysaccharides Composition and Applications
Authors: Muhammad Hazwan Hamzah | Nurbalqis Zulkefli | Adila Fazliyana Aili Hamzah | Rosnah Shamsudin | Hasfalina Che Man | Abd Halim Md Ali | Maimunah Mohd Ali | Bernard Maringgal | Mohd Hafizz Wondi
Source: Food Analytical Methods (article, 2024-04-19)
Field: Chemistry — Analytical Chemistry

Optimization of Process Parameters Using Response Surface Methodology for Essential Oil Extraction from Canarium odontophyllum Kernels by Subcritical Water Treatment Response surface methodology ; Extraction (chemistry) ; Process (computing) ; Water extraction ; Mathematics ; Chromatography ; Chemistry ; Computer science Petroleum Processing and Analysis ; Subcritical and Supercritical Water Processes ; Essential Oils and Antimicrobial Activity
Authors: Yuzuka Onaka | Renki Sakai | T. Fukunaga | Koki Ikemoto | Hiroyuki Isobe
Source: Angewandte Chemie International Edition (article, 2024-04-06)
Field: Chemistry — Organic Chemistry

Bayesian Inference for Model Analyses of Supramolecular Complexes: A Case Study with Nanocarbon Hosts A 126 π-electron nanobowl molecule, phenine tridehydrosumanene, was synthesized in 12 steps through the development of a polygon cyclization strategy that assembled the polygonal precursors by Ni-mediated macrocyclization. The bowl-shaped structure accommodated C<sub>70</sub> as a guest at the concave site, and the ball-in-bowl structure was determined by X-ray crystallography. The host-guest equilibrium in solution was studied with titration experiments using isothermal calorimetry, which provided an interesting test case for studying the host-guest stoichiometry. Bayesian inference was introduced for stoichiometric analyses of the equilibrium, and a procedure to estimate the volume of prior probability in the parameter space was developed. The Bayesian procedure functioned as Occam's razor and provided quantitative support for a specific stoichiometry. The method was examined with five host-guest examples comprising nanocarbon hosts, which suggested the versatility of Bayesian inference for studies of supramolecular complexes. Inference ; Bayesian inference ; Bayesian probability ; Computer science ; Supramolecular chemistry ; Artificial intelligence ; Machine learning ; Chemistry Supramolecular Chemistry and Complexes ; Metal-Organic Frameworks: Synthesis and Applications ; Crystallography and molecular interactions
Authors: Jia-Xin Li | Chun-Chun Qing | Xiu-Qian Wang | Meijia Zhu | Boya Zhang | Zhengyong Zhang
Source: Current Research in Food Science (article, 2024-01-01)
Field: Chemistry — Analytical Chemistry

Discriminative feature analysis of dairy products based on machine learning algorithms and Raman spectroscopy Discriminant analysis of similar food samples is an important aspect of achieving food quality control. The effective combination of Raman spectroscopy and machine learning algorithms has become an extremely attractive approach to develop intelligent discrimination techniques. Feature spectral analysis can help researchers gain a deeper understanding of the data patterns in food quality discrimination. Herein, this work takes the discrimination of three brands of dairy products as an example to investigate the Raman spectral feature based on the support vector machines (SVM), extreme learning machines (ELM) and convolutional neural network (CNN) algorithms. The results show that there are certain differences in the optimal spectral feature interval corresponding to different machine learning algorithms. Selecting the appropriate spectral feature interval can maintain high recognition accuracy and improve the computational efficiency of the algorithm. For example, the SVM algorithm has a recognition accuracy of 100% in the 890-980 cm<sup>-1</sup>, 1410-1500 cm<sup>-1</sup> fusion spectral range, which takes about 200 s. The ELM algorithm also has a recognition accuracy of 100% in the 890-980 cm<sup>-1</sup>, 1410-1500 cm<sup>-1</sup> fusion spectral range, which takes less than 0.3 s. The CNN algorithm has a recognition accuracy of 100% in the 890-980 cm<sup>-1</sup>, 1050-1180 cm<sup>-1</sup>, 1410-1500 cm<sup>-1</sup> fusion spectral range, which takes about 80 s. In addition, by analyzing the distribution of spectral feature intervals based on Euclidean distance, the distribution of experimental samples based on feature spectra is visually displayed. Through the spectral feature analysis process of similar samples, a set of analysis strategies is provided to deeply reveal the data foundation of classification algorithms, which can provide reference for the analysis of relevant discriminative research patterns. Artificial intelligence ; Feature (linguistics) ; Discriminative model ; Extreme learning machine ; Pattern recognition (psychology) ; Support vector machine ; Computer science ; Algorithm ; Linear discriminant analysis ; Convolutional neural network ; Machine learning ; Artificial neural network Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Advanced Chemical Sensor Technologies
Authors: Maria G. Rasteiro | Antti Koponen
Source: Powders (review, 2024-03-14)
Field: Chemistry — Physical and Theoretical Chemistry

Monitoring Aggregation Processes in Multiphase Systems: A Review Particle aggregation is essential in many industrial processes, spanning the pharmaceutical and food industries, polymer production, and the environment, among others. However, aggregation can also occur, in some processes, as a non-desired side effect. Thus, to be able to monitor aggregation in industrial processes is of high importance to guarantee that the final, required product characteristics are obtained. In this paper, we present an extensive review of the different techniques available for monitoring particle characteristics in industrial processes involving particulate materials, with special emphasis on aggregation processes. These methods include both off-line and on-line techniques, based either on image acquisition techniques or different radiation scattering techniques (light-scattering and ultrasound spectroscopy). The principles behind each technique are addressed, together with their relevant applications, advantages, and disadvantages. Computer science Electrostatics and Colloid Interactions ; Minerals Flotation and Separation Techniques ; Coagulation and Flocculation Studies
Authors: Frédéric A. Perras | Alexander L. Paterson
Source: Solid State Nuclear Magnetic Resonance (article, 2024-04-07)
Field: Chemistry — Spectroscopy

Automatic fitting of multiple-field solid-state NMR spectra Maxima and minima ; Computation ; Spectral line ; Algorithm ; Field (mathematics) ; Computer science ; NMR spectra database ; Parameter space ; Statistical physics ; Magic angle spinning ; Biological system ; Computational physics ; Physics ; Mathematics ; Statistics ; Mathematical analysis ; Quantum mechanics Advanced NMR Techniques and Applications ; NMR spectroscopy and applications ; Muon and positron interactions and applications
Authors: Hao Li | Gen Liu | Yi Zhang | Luzhen Hao | Pinggen Zou | Yuchen Xu | Mei Ji | Xuebin Yu | Jiangli Li | Yanqing Ma | Lei Ma
Source: Journal of Materials Science Materials in Engineering (article, 2024-12-04)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Study of SERS activity of different gold nanostructures prepared by electron beam lithography Abstract Plasmonic metal nanostructure prepared by photolithography technology can be used as a uniform and stable substrate with high SERS activity. However, there is only limited research on the precisely regulated metal nanostructures and the systematic studies on the relation between the structure and SERS response. Herein, different gold nanostructure arrays (including circles, equilateral triangles, squares, regular pentagons, regular hexagons, pentagrams, and hexagram) have been prepared using electron beam lithography (EBL). Rhodamine B were employed as the probe molecule. The effect of the shapes, sizes (s), spacing (d), and rotation angle (α) of different shapes gold on SERS activities were systematically investigated under the excitation of 532 nm laser. Further finite element method based electromagnetic field simulations unveiled the correlation between the local electromagnetic field strengths and the SERS activities, which also verified the proportional relation between the fourth power of the electromagnetic field intensity (L E ) and enhancement factor (EF). Electron-beam lithography ; Materials science ; Lithography ; Nanostructure ; Nanotechnology ; Cathode ray ; Electron ; Optoelectronics ; Resist ; Physics ; Layer (electronics) Gold and Silver Nanoparticles Synthesis and Applications ; Nanocluster Synthesis and Applications ; Quantum Dots Synthesis And Properties
Authors: Kyle Barlow | Ryan Phelps | Julien Eng | Tetsuo Katayama | Erica Sutcliffe | Marco Coletta | Euan K. Brechin | Thomas J. Penfold | J. Olof Johansson
Source: Nature Communications (article, 2024-05-14)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Tracking nuclear motion in single-molecule magnets using femtosecond X-ray absorption spectroscopy The development of new data storage solutions is crucial for emerging digital technologies. Recently, all-optical magnetic switching has been achieved in dielectrics, proving to be faster than traditional methods. Despite this, single-molecule magnets (SMMs), which are an important class of magnetic materials due to their nanometre size, remain underexplored for ultrafast photomagnetic switching. Herein, we report femtosecond time-resolved K-edge X-ray absorption spectroscopy (TR-XAS) on a Mn(III)-based trinuclear SMM. Exploiting the elemental specificity of XAS, we directly track nuclear dynamics around the metal ions and show that the ultrafast dynamics upon excitation of a crystal-field transition are dominated by a magnetically active Jahn-Teller mode. Our results, supported by simulations, reveal minute bond length changes from 0.01 to 0.05 Å demonstrating the sensitivity of the method. These geometrical changes are discussed in terms of magneto-structural relationships and consequently our results illustrate the importance of TR-XAS for the emerging area of ultrafast molecular magnetism. Femtosecond ; Tracking (education) ; Spectroscopy ; Absorption (acoustics) ; Magnet ; Nuclear magnetic resonance ; Materials science ; Molecule ; Atomic physics ; Physics ; Molecular physics ; Optics ; Laser Magnetism in coordination complexes ; Advanced Electron Microscopy Techniques and Applications ; Advanced MRI Techniques and Applications
Authors: Cassandra Remple | Jesse Huso | Marc H. Weber | John S. McCloy | Matthew D. McCluskey
Source: Journal of Applied Physics (article, 2024-05-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Electron irradiation effects on the optical properties of Hf- and Zn-doped <i>β</i>-Ga2O3 Optical and electrical properties of Hf- and Zn-doped β-Ga2O3 samples, which are n-type and insulating, respectively, were altered via high-energy electron irradiation at 2.5 or 0.5 MeV. The β-Ga2O3:Hf samples irradiated with 2.5 MeV electrons experienced a color change from blue to yellow and a large drop in conductivity, attributed to the creation of gallium vacancies, which compensate donors. This irradiation resulted in the absence of free carrier absorption and the presence of Cr3+ photoluminescence (PL). PL mapping prior to irradiation revealed optically active ZnO precipitates that formed during the growth of β-Ga2O3:Zn. These precipitates have a 384 nm (3.23 eV) stacking fault emission in the core; in the outer shell of the precipitate, the PL blue-shifts to 377 nm (3.29 eV) and a broad defect band is observed. After 0.5 MeV electron irradiation, the defect band broadened and increased in intensity. The blue PL band (435 nm) of β-Ga2O3 was enhanced for both Hf- and Zn-doped samples irradiated with 0.5 MeV. This enhancement is correlated with an increase in oxygen vacancies. Photoluminescence ; Irradiation ; Doping ; Materials science ; Electron beam processing ; Analytical Chemistry (journal) ; Gallium ; Chemistry ; Optoelectronics ; Metallurgy Ga2O3 and related materials ; ZnO doping and properties ; Advanced Photocatalysis Techniques
Authors: Jin Chang | Wenye Ji | Xiong Yao | Arnold J. van Run | Simon Gröblacher
Source: Nano Letters (article, 2024-05-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Broadband, High-Reflectivity Dielectric Mirrors at Wafer Scale: Combining Photonic Crystal and Metasurface Architectures for Advanced Lightsails Highly ambitious initiatives aspire to propel a miniature spacecraft to a neighboring star within a human generation, leveraging the radiation pressure of lasers for propulsion. One major challenge for this enormous feat is to build a meter-scale, ultralow mass lightsail with broadband reflectivity. In this work, we present the design and fabrication of a lightsail composed of two distinct dielectric layers with photonic crystal/metasurface structure covering a 4" wafer. We achieved broadband reflection of >70% spanning over the full Doppler-shifted laser wavelength range during spacecraft acceleration with a low total mass in the range of a few grams when scaled up to meter size. Furthermore, we find new paths to reliably fabricate these subwavelength structures over macroscopic areas and then systematically characterize their optical performance, confirming their suitability for future lightsail applications. Our innovative device and precise nanofabrication approaches represent a significant leap toward interstellar exploration. Broadband ; Materials science ; Optoelectronics ; Wafer ; Dielectric ; Photonic crystal ; Optics ; Spacecraft ; Laser ; Photonics ; Fabrication ; Reflection (computer programming) ; Physics ; Aerospace engineering ; Computer science ; Engineering Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Advanced Materials and Mechanics
Authors: Stefano Racioppi | Alberto Otero‐de‐la‐Roza | Samad Hajinazar | Eva Zurek
Source: Digital Discovery (article, 2024-11-06)
Field: Materials Science — Materials Chemistry

Powder X-ray diffraction assisted evolutionary algorithm for crystal structure prediction First PXRD assisted crystal structure prediction method that can correct for temperature, strain, and choice of computational method. Diffraction ; Algorithm ; X-ray crystallography ; Crystallography ; X-ray ; Materials science ; Computer science ; Physics ; Optics ; Chemistry X-ray Diffraction in Crystallography
Authors: Raja Venkatesan | M. Vishnuvarthanan | Eswaran Kamaraj | Maher M. Alrashed | Seong‐Cheol Kim
Source: Polymers for Advanced Technologies (article, 2024-12-01)
Field: Materials Science — Biomaterials

Investigation of the Physicochemical and Antibacterial Activities of Plant Extract of Juniperus communis L. With Poly(Butylene Adipate‐Co‐Terephthalate) Films for Food Packaging ABSTRACT In this work, a plant‐based composite materials that can be used as food packaging has been developed. Juniperus communis L. extract, which is known to have good antibacterial activity, was added to poly(butylene adipate‐co‐terephthalate) (PBAT) at different percentage (1%, 5%, 10%, 15%, 20%) and produced films by solution casting method. All the prepared PBAT films were subjected to characterization techniques like attenuated total reflection‐infrared spectroscopy (ATR‐IR), x‐ray diffraction (XRD), surface morphology, thermal stability, mechanical strength, film color, opacity, wettability, and antibacterial properties. Thermogravimetric analysis (TGA) was conducted on thermal stability of PBAT composite films. To examine the suitability of composite films for food packaging, measurements on opacity and water vapor permeability have been performed. It was determined that the higher the percentage of Juniperus communis L., which enhanced the test results. The PBAT composite films' antibacterial activity against both gram‐positive ( S. aureus ) and gram‐negative ( E. coli ) bacteria was tested. The optimum antibacterial activity against S. aureus and E. coli was observed in the PBAT composite film with 20% of Juniperus communis L. plant extract. However, it can be supposed that the food packaging characteristics are improved by adding Juniperus communis L. plant extract to the PBAT. Adipate ; Materials science ; Food packaging ; Food science ; Polymer chemistry ; Biology biodegradable polymer synthesis and properties ; Nanocomposite Films for Food Packaging ; Biopolymer Synthesis and Applications
Authors: Bushra Akram | Aisha Umar | M. Ajmal Ali | Mohamed S. Elshikh | Chinenye Adaobi Igwegbe | Rashid Iqbal | Soumya Ghosh
Source: BMC Biotechnology (article, 2024-10-30)
Field: Materials Science — Materials Chemistry

Kinetic and thermodynamic analysis of alizarin Red S biosorption by Alhagi maurorum: a sustainable approach for water treatment Synthetic dyes, such as Alizarin Red S, contribute significantly to environmental pollution. This study investigates the biosorption potential of Alhagi maurorum biosorbent for the removal of Alizarin Red S (ARS) from aqueous solutions. Fourier transform infrared spectroscopy (FTIR) was used to analyze the biosorbent's adsorption sites. Various parameters were optimized to maximize dye adsorption. An optimal removal efficiency of 82.26% was attained by employing 0.9 g of biosorbent with a 25 ppm dye concentration at pH 6 and 60 °C over 30 min. The data were modeled using various isothermal and kinetic models to understand the adsorption behavior. Thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The pseudo-second-order kinetic model best described the data, indicating chemisorption as the rate-limiting step. The data matched best to the Langmuir model, indicating that the adsorption occurs as a monolayer on uniform surfaces with a finite number of binding sites. The model showed a strong correlation (R² = 0.991) and a maximum adsorption capacity (q<sub>max</sub>) of 8.203 mg/g. Principal component analysis (PCA) identified temperature as the dominant factor, with the primary component, PC1 capturing 100% of its effect. The mechanisms involved in ARS biosorption on A. maurorum include electrostatic interactions, hydrogen bonding, hydrophobic interactions, dipole-dipole interactions, and π-π stacking. Alhagi maurorum showed promising potential for biosorbing toxic dyes from contaminated water, suggesting further investigation for practical applications. Biosorption ; ALIZARIN RED ; Biology ; Alizarin ; Nuclear chemistry ; Adsorption ; Chemistry ; Physical chemistry Crystallization and Solubility Studies ; Adsorption and biosorption for pollutant removal ; Chemical and Physical Properties in Aqueous Solutions
Authors: Panagiota Siachouli | Katerina S. Karadima | Vlasis G. Mavrantzas | Spyros Ν. Pandis
Source: Soft Matter (article, 2024-01-01)
Field: Materials Science — Ceramics and Composites

The effect of functional groups on the glass transition temperature of atmospheric organic compounds: a molecular dynamics study Organic compounds constitute a substantial part of atmospheric particulate matter not only in terms of mass concentration but also in terms of distinct functional groups. The glass transition temperature provides an indirect way to investigate the phase state of the organic compounds, playing a crucial role in understanding their behavior and influence on aerosol processes. Molecular dynamics (MD) simulations were implemented here to predict the glass transition temperature (<i>T</i><sub>g</sub>) of atmospherically relevant organic compounds as well as the influence of their functional groups and length of their carbon chain. The cooling step used in the simulations was chosen to be neither too low (to supress crystallization) nor too high (to avoid <i>T</i><sub>g</sub> overprediction). According to the MD simulations, the predicted <i>T</i><sub>g</sub> is sensitive to the functional groups as follows: carboxylic acid (-COOH) > hydroxyl (-OH) and (-COOH) > carbonyls (-CO). Increasing the number of carbon atoms leads to higher <i>T</i><sub>g</sub> for the linearly structured compounds. Linear compounds with lower molecular weight were found to exhibit a lower <i>T</i><sub>g</sub>. No clear correlation between O : C and <i>T</i><sub>g</sub> was observed. The architecture of the carbon chain (linear, or branched, or ring) was also found to impact the glass transition temperature. Compounds containing a non-aromatic carbon ring are characterized by a higher <i>T</i><sub>g</sub> compared to linear and branched ones with the same number of carbon atoms. Glass transition ; Particulates ; Chemical physics ; Molecular dynamics ; Chemistry ; Transition (genetics) ; Density functional theory ; Organic matter ; Environmental chemistry ; Thermodynamics ; Materials science ; Computational chemistry ; Organic chemistry ; Physics ; Polymer Glass properties and applications ; Atmospheric chemistry and aerosols ; Adsorption, diffusion, and thermodynamic properties of materials