jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Lei Zhang | Jun Yan Dai | Massimo Moccia | Giuseppe Castaldi | Tie Jun Cui | Vincenzo Galdi
Source: EPJ Applied Metamaterials (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Recent advances and perspectives on space-time coding digital metasurfaces Within the overarching framework of space-time metastructures, digital metasurfaces based on spatio-temporal coding are emerging as powerful and versatile architectures for complex field manipulations, also in view of their inherently programmable nature. Here, we provide a compact survey of our recent results and ongoing studies in this research area. Examples of field manipulations include harmonic beam steering and/or shaping and programmable nonreciprocal effects. Possible applications are abundant and range from wireless communications to radars and imaging. Computer science ; Field-programmable gate array ; Coding (social sciences) ; Beam steering ; Wireless ; Reconfigurability ; Electronic engineering ; Telecommunications ; Computer hardware ; Engineering Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Antenna Design and Analysis
Authors: M. Gomez de la Calle | J. M. Martínez-Tarifa | Angel Manuel Gomez Solanilla | Guillermo Robles
Source: IEEE Access (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Uncertainty Sources in the Estimation of the Partial Discharge Inception Voltage in Turn-to-Turn Insulation Systems Partial discharges (PD) are one of the main causes of premature failure in low-voltage motors driven by variable-speed drives. The use of these control systems are being quite extended due to new applications, such as the more electric aircraft (MEA) or hybrid and electric vehicles, and this has pushed research towards appropriate designs of electric motors to avoid, as much as possible, the presence of PD within their windings. This article presents a model to predict the partial discharge inception voltage (PDIV) in the insulation of low-voltage machines. A value for the secondary ionization coefficient based on a statistical study is also proposed. The deviations of the model are also studied by obtaining the uncertainty of the value of that coeficient and the predicted values of the PDIV for a set of wires. This uncertainty will be compared with other error sources such as generator harmonics and humidity. Finally, the tests are done for different temperatures extend the model applicability. Partial discharge ; Voltage ; Electromagnetic coil ; Harmonics ; Control theory (sociology) ; Generator (circuit theory) ; Insulation system ; Computer science ; Automotive engineering ; Electrical engineering ; Engineering ; Power (physics) ; Physics ; Control (management) High voltage insulation and dielectric phenomena ; Electrostatic Discharge in Electronics ; Electrical Fault Detection and Protection
Authors: Konstantinos Konstantinou | Juraj Mavračić | Felix C. Mocanu | Stephen R. Elliott
Source: physica status solidi (b) (article, 2020-11-17)
Field: Materials Science — Materials Chemistry

Simulation of Phase‐Change‐Memory and Thermoelectric Materials using Machine‐Learned Interatomic Potentials: Sb<sub>2</sub>Te<sub>3</sub> Density‐functional‐theory (DFT)‐based, ab initio molecular dynamics (AIMD) simulations of amorphous materials generally suffer from three computer‐resource‐related limitations due to their O( N 3 ) cubic scaling with model system size, N . They are limited to a maximum model size of N ≈500 atoms; they are limited to time scales &lt;1 ns; and, usually, only a single model can be simulated in any one investigation. This article discusses a machine‐learned, linear‐scaling (O( N )), DFT‐accurate interatomic potential (a Gaussian approximation potential, GAP), originally developed by Mocanu et al. [ J. Phys. Chem. B 2018, 122 , 8998] using a Gaussian process regression method for the ternary phase‐change‐memory material Ge 2 Sb 2 Te 5 (GST). The chemical transferability of this GAP potential is explored in an application to the case of simulating amorphous models of the phase‐change‐memory and thermoelectric material Sb 2 Te 3 , an end‐member of the GST compositional tie‐line GeTe–Sb 2 Te 3 . The GAP‐model results are compared with those obtained from conventional DFT‐based AIMD simulations. Scaling ; Density functional theory ; Ternary operation ; Amorphous solid ; Phase-change memory ; Interatomic potential ; Materials science ; Ab initio ; Molecular dynamics ; Band gap ; Gaussian ; Condensed matter physics ; Statistical physics ; Thermodynamics ; Physics ; Chemistry ; Computer science ; Computational chemistry ; Mathematics ; Quantum mechanics ; Crystallography ; Phase change Phase-change materials and chalcogenides ; Machine Learning in Materials Science ; Chalcogenide Semiconductor Thin Films
Authors: Ancuta Moga | María Vergara‐Barberán | Marı́a Jesús Lerma-García | José Manuel Herrero‐Martínez | Ernesto Francisco Simó‐Alfonso
Source: Microchemical Journal (article, 2020-05-03)
Field: Chemistry — Analytical Chemistry

Poly(ethylene glycol) diacrylate-based solid-phase extraction for determination of sulfonamides in meat samples Sorbent ; Chromatography ; Solid phase extraction ; Extraction (chemistry) ; Sulfapyridine ; Chemistry ; Ethylene glycol ; Elution ; Sulfamerazine ; Sulfathiazole ; Sulfadiazine ; High-performance liquid chromatography ; Organic chemistry ; Adsorption Analytical chemistry methods development ; Pesticide Residue Analysis and Safety ; Pharmacological Effects and Assays
Authors: Avijit Das | Kousik Maji | Sarajit Naskar | Uttam Manna
Source: Chemical Science (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Facile optimization of hierarchical topography and chemistry on magnetically active graphene oxide nanosheets ‘Confined-optimization’ of desired topography and appropriate chemistry on a magnetically-active and two-dimensional (2D) graphene oxide (GO) nanosheets is unprecedentedly achieved following a rapid and facile 1,4-conjugate addition reaction. Graphene ; Oxide ; Conjugate ; Nanotechnology ; Materials science ; Chemistry ; Chemical engineering ; Organic chemistry ; Engineering Graphene research and applications ; Covalent Organic Framework Applications ; Advanced Photocatalysis Techniques
Authors: Ibrahim Hotan Alsohaimi | Mohammad Rizwan Khan | Hazim M. Ali | Mohammad Azam | Ahmed Moid Alammari
Source: Scientific Reports (article, 2020-03-23)
Field: Chemistry — Spectroscopy

Solvent extraction and gas chromatography–mass spectrometric determination of probable carcinogen 1,4-dioxane in cosmetic products In the present work, a method based on solvent extraction and gas chromatography-mass spectrometry (GC-MS) has been validated for the determination of 1,4-dioxane in cosmetics. Various solvents including ethyl acetate, hexane, methanol, dichloromethane and acetone have been used for the extraction of 1,4-dioxane, among them the ethyl acetate was found to be the most efficient extracting solvent. This method has offered excellent quality parameters for instance linearity (R<sup>2</sup> > 0.9991), limit of detection (LOD, 0.00065-0.00091 µg/mL), limit of quantification (LOQ, 0.00217-0.00304 µg/mL) and, precision intra-day (1.65-2.60%, n = 5) and inter-day (0.16-0.32%, n = 5) in terms of relative standard deviation (RSD%). A total of thirty-nine cosmetic samples of different brands and origin have been studied. Among them, the 1,4-dioxane was found in twenty-three samples (FB<sub>1</sub>-FB<sub>7</sub>, MC<sub>1</sub>-MC<sub>4</sub>, MC<sub>6</sub>-MC<sub>8</sub>, HS<sub>3</sub>, HS<sub>5</sub>, BL<sub>1</sub>-BL<sub>3</sub>, BL<sub>5</sub> and PLD<sub>1</sub>-PLD<sub>3</sub>) at the levels between 0.15 µg/mL and 9.92 µg/mL, whereas in sixteen samples (MC<sub>5</sub>, HS<sub>1</sub>, HS<sub>2</sub>, SG<sub>1</sub>-SG<sub>5</sub>, BL<sub>4</sub> and HP<sub>1</sub>- HP<sub>6</sub>) was found to be not detected. The recovery values were achieved between 93% and 99% in both low and high level of spiked samples. In comparison to the traditional analytical techniques, the proposed method was found to be very sensitive and cost-effective for the routine analysis of 1,4-dioxane at low concentration in cosmetics. Detection limit ; Dichloromethane ; Chromatography ; Ethyl acetate ; Solvent ; Chemistry ; Extraction (chemistry) ; Gas chromatography–mass spectrometry ; Acetone ; Gas chromatography ; Mass spectrometry ; Hexane ; Organic chemistry Analytical Chemistry and Chromatography ; Effects and risks of endocrine disrupting chemicals ; Advanced Chemical Sensor Technologies
Authors: Caleb M. Bunton | Zahra M. Bassampour | Jennifer M. Boothby | Ashanti N. Smith | Joseph V. Rose | Daphne M. Nguyen | Taylor H. Ware | Karl G. Csaky | Alexander R. Lippert | Nicolay V. Tsarevsky | David Y. Son
Source: Macromolecules (article, 2020-11-16)
Field: Materials Science — Polymers and Plastics

Degradable Silyl Ether–Containing Networks from Trifunctional Thiols and Acrylates The purpose of this study was the synthesis of novel degradable polymer-based devices capable of releasing an encapsulated agent in a controlled manner with specific interest for use as drug delivery materials. Base-catalyzed thiol Michael additions between trithiols and triacrylates containing silyl ether groups were exploited to prepare a series of degradable cross-linked networks. Disodium fluorescein was loaded as a hydrophilic drug surrogate inside the networks, and the degradation of the networks and the release of dye were monitored. The networks were characterized by Fourier transform infrared spectroscopy, and their thermal and mechanical properties were investigated through thermogravimetric analysis and dynamic mechanical analysis. The effects of the monomer structure on degradation, release behavior, and thermal properties were investigated. The networks prepared from more sterically hindered silyl ether monomers exhibited decreased rates of degradation and correspondingly slower release of encapsulated disodium fluorescein dye. The results suggest that the characteristics of the networks can be fine-tuned by manipulation of the group attached to the Si atom in the silyl ether monomers. Silyl ether ; Monomer ; Thermogravimetric analysis ; Silylation ; Ether ; Polymer chemistry ; Chemistry ; Polymer ; Fourier transform infrared spectroscopy ; Pentaerythritol ; Organic chemistry ; Chemical engineering ; Catalysis Synthesis and properties of polymers ; biodegradable polymer synthesis and properties ; Antimicrobial agents and applications
Authors: Sandra Pacharra | Seán McMahon | Patrick E. Duffy | Pooja Basnett | Wenfa Yu | Sabine Seisel | Ulrik Stervbo | Nina Babel | Ipsita Roy | Richard Viebahn | Wenxin Wang | Jochen Salber
Source: Frontiers in Bioengineering and Biotechnology (article, 2020-08-13)
Field: Materials Science — Biomaterials

Cytocompatibility Evaluation of a Novel Series of PEG-Functionalized Lactide-Caprolactone Copolymer Biomaterials for Cardiovascular Applications Although the use of bioresorbable materials in stent production is thought to improve long-term safety compared to their durable counterparts, a recent FDA report on the 2-year follow-up of the first FDA-approved bioresorbable vascular stent showed an increased occurrence of major adverse cardiac events and thrombosis in comparison to the metallic control. In order to overcome the issues of first generation bioresorbable polymers, a series of polyethylene glycol-functionalized poly-L-lactide-co-ε-caprolactone copolymers with varying lactide-to-caprolactone content is developed using a novel one-step PEG-functionalization and copolymerization strategy. This approach represents a new facile way toward surface enhancement for cellular interaction, which is shown by screening these materials regarding their cyto- and hemocompatibility in terms of cytotoxicity, hemolysis, platelet adhesion, leucocyte activation and endothelial cell adhesion. By varying the lactide-to-caprolactone polymer composition, it is possible to gradually affect endothelial and platelet adhesion which allows fine-tuning of the biological response based on polymer chemistry. All polymers developed were non-cytotoxic, had acceptable leucocyte activation levels and presented non-hemolytic (<2% hemolysis rate) behavior except for PLCL-PEG 55:45 which presented hemolysis rate of 2.5% ± 0.5. Water contact angles were reduced in the polymers containing PEG functionalization (PLLA-PEG: 69.8° ± 2.3, PCL-PEG: 61.2° ± 7.5) versus those without (PLLA: 79.5° ± 3.2, PCL: 76.4° ± 10.2) while the materials PCL-PEG550, PLCL-PEG550 90:10 and PLCL-PEG550 70:30 demonstrated best endothelial cell adhesion. PLLA-PEG550 and PLCL-PEG550 70:30 presented as best candidates for cardiovascular implant use from a cytocompatibility perspective across the spectrum of testing completed. Altogether, these polymers are excellent innovative materials suited for an application in stent manufacture due to the ease in translation of this one-step synthesis strategy to device production and their excellent <i>in vitro</i> cyto- and hemocompatibility. Copolymer ; Caprolactone ; PEG ratio ; Lactide ; Materials science ; Polymer chemistry ; Polymer ; Composite material biodegradable polymer synthesis and properties ; Electrospun Nanofibers in Biomedical Applications ; Tissue Engineering and Regenerative Medicine
Authors: Thiago B. Taketa | João Batista Maia Rocha Neto | Danilo M. dos Santos | Anderson Fiamingo | Marisa Masumi Beppu | Sérgio Paulo Campana Filho | Robert E. Cohen | Michael F. Rubner
Source: Langmuir (article, 2020-04-21)
Field: Materials Science — Surfaces, Coatings and Films

Tracking Sulfonated Polystyrene Diffusion in a Chitosan/Carboxymethyl Cellulose Layer-by-Layer Film: Exploring the Internal Architecture of Nanocoatings Since chitosan presents the ability to interact with a wide range of molecules, it has been one of the most popular natural polymers for the construction of layer-by-layer thin films. In this study, depth-profiling X-ray photoelectron spectroscopy (XPS) was employed to track the diffusion of sulfonated polystyrene (SPS) in carboxymethyl cellulose/chitosan (CMC/Chi) multilayers. Our findings suggest that the CMC/Chi film does not constitute an electrostatic barrier sufficient to block diffusion of SPS, and that diffusion can be controlled by adjusting the diffusion time and the molecular weight of the polymers that compose the CMC/Chi system. In addition to monitoring the diffusion, it was also possible to observe a process of preferential interaction between Chi and SPS. Thus, the nitrogen N 1s peak, due to functional groups found exclusively in chitosan chains, was the key factor to identifying the molecular interactions involving chitosan and the different polyanions. Accordingly, the presence of a strong polyanion such as SPS shifts the N 1s peak to a higher level of binding energy. Such results highlight that understanding the fundamentals of polymer interactions is a major step to fine-tuning the internal architecture of LbL structures for specific applications (e.g., drug release). Chitosan ; Carboxymethyl cellulose ; X-ray photoelectron spectroscopy ; Polystyrene ; Polymer ; Materials science ; Chemical engineering ; Layer by layer ; Diffusion ; Cellulose ; Polymer chemistry ; Molecule ; Layer (electronics) ; Nanotechnology ; Chemical physics ; Chemistry ; Organic chemistry ; Composite material ; Thermodynamics Polymer Surface Interaction Studies ; Molecular Junctions and Nanostructures ; Nanocomposite Films for Food Packaging
Authors: Gerardo Campos-Villalobos | Flor R. Siperstein | Arvin Charles | Alessandro Patti
Source: Journal of Colloid and Interface Science (article, 2020-03-24)
Field: Materials Science — Materials Chemistry

Solvent-induced morphological transitions in methacrylate-based block-copolymer aggregates Copolymer ; Lamellar structure ; Materials science ; Vesicle ; Phase diagram ; Tetrahydrofuran ; Methacrylate ; Phase (matter) ; Morphology (biology) ; Chemical engineering ; Self-assembly ; Polymer chemistry ; Solvent ; Nanotechnology ; Chemistry ; Membrane ; Polymer ; Organic chemistry ; Composite material Block Copolymer Self-Assembly ; Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems
Authors: Armando Navarro‐Huerta | Marcus J. Jellen | Jessica Arcudia | Simon J. Teat | Rubén A. Toscano | Gabriel Merino | Braulio Rodríguez‐Molina
Source: Chemical Science (article, 2020-12-14)
Field: Chemistry — Physical and Theoretical Chemistry

Tailoring the cavities of hydrogen-bonded amphidynamic crystals using weak contacts: towards faster molecular machines This work describes the use of C-H⋯F-C contacts in the solid-state from the stator towards the rotator to fine-tune their internal motion, by constructing a set of interactions that generate close-fitting cavities in three supramolecular rotors <b>1-3I</b>. The crystal structures of these rotors, determined by synchrotron radiation experiments at different temperatures, show the presence of such C-H⋯F-C contacts between extended carbazole stators featuring fluorinated phenyl rings and the 1,4-diazabicyclo[2.2.2]octane (DABCO) rotator. According to the <sup>2</sup>H NMR results, using deuterated samples, and periodic density functional theory computations, the rotators experience fast angular displacements (preferentially 120° jumps) due to their low rotational activation energies (<i>E</i> <sub>a</sub> = 0.8-2.0 kcal mol<sup>-1</sup>). The higher rotational barrier for <b>1</b> (2.0 kcal mol<sup>-1</sup>) is associated with a larger number of weak C-H⋯F-C contacts generated by the stators. This strategy offers the possibility to explore the correlation among weak intermolecular forces, cavity shape, and internal dynamics, which has strong implications in the design of future fine-tuned amphidynamic crystals. Intermolecular force ; Supramolecular chemistry ; Octane ; Rotational dynamics ; Crystallography ; Spins ; Deuterium ; Molecular dynamics ; Chemistry ; Hydrogen bond ; Chemical physics ; DABCO ; Molecular machine ; Materials science ; Crystal structure ; Molecule ; Computational chemistry ; Nanotechnology ; Atomic physics ; Physics ; Condensed matter physics Crystallography and molecular interactions ; Supramolecular Chemistry and Complexes ; Luminescence and Fluorescent Materials
Authors: Lorenz Lindenthal | Thomas Ruh | Raffael Rameshan | Harald Summerer | Andreas Nenning | Christopher Herzig | Stefan Löffler | Andreas Limbeck | Alexander Karl Opitz | Peter Blaha | Christoph Rameshan
Source: Acta Crystallographica Section B Structural Science Crystal Engineering and Materials (article, 2020-11-14)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Ca-doped rare earth perovskite materials for tailored exsolution of metal nanoparticles Perovskite-type oxide materials (nominal composition ABO<sub>3</sub>) are a very versatile class of materials, and their properties are tuneable by varying and doping A- and B-site cations. When the B-site contains easily reducible cations (e.g. Fe, Co or Ni), these can exsolve under reducing conditions and form metallic nanoparticles on the surface. This process is very interesting as a novel route for the preparation of catalysts, since oxide surfaces decorated with finely dispersed catalytically active (often metallic) nanoparticles are a key requirement for excellent catalyst performance. Five doped perovskites, namely, La<sub>0.9</sub>Ca<sub>0.1</sub>FeO<sub>3-δ</sub>, La<sub>0.6</sub>Ca<sub>0.4</sub>FeO<sub>3-δ</sub>, Nd<sub>0.9</sub>Ca<sub>0.1</sub>FeO<sub>3-δ</sub>, Nd<sub>0.6</sub>Ca<sub>0.4</sub>FeO<sub>3-δ</sub> and Nd<sub>0.6</sub>Ca<sub>0.4</sub>Fe<sub>0.9</sub>Co<sub>0.1</sub>O<sub>3-δ</sub>, have been synthesized and characterized by experimental and theoretical methods with respect to their crystal structures, electronic properties, morphology and exsolution behaviour. All are capable of exsolving Fe and/or Co. Special emphasis has been placed on the influence of the A-site elemental composition on structure and exsolution capability. Using Nd instead of La increased structural distortions and, at the same time, hindered exsolution. Increasing the amount of Ca doping also increased distortions and additionally changed the Fe oxidation states, resulting in exsolution being shifted to higher temperatures as well. Using the easily reducible element Co as the B-site dopant significantly facilitated the exsolution process and led to much smaller and homogeneously distributed exsolved particles. Therefore, the Co-doped perovskite is a promising material for applications in catalysis, even more so as Co is catalytically a highly active element. The results show that fine-tuning of the perovskite composition will allow tailored exsolution of nanoparticles, which can be used for highly sophisticated catalyst design. Dopant ; Doping ; Materials science ; Perovskite (structure) ; Metal ; Oxide ; Nanoparticle ; Catalysis ; Crystal structure ; Chemical engineering ; Nanotechnology ; Crystallography ; Chemistry ; Metallurgy ; Optoelectronics Magnetic and transport properties of perovskites and related materials ; Catalytic Processes in Materials Science ; Layered Double Hydroxides Synthesis and Applications
Authors: Matthias Windhagauer | Raffaela M. Abbriano | J. R. Ashworth | Lorenzo Barolo | Ana Cristina Jaramillo-Madrid | Mathieu Pernice | Martina A. Doblin
Source: Algal Research (article, 2020-12-23)
Field: Materials Science — Biomaterials

Characterisation of novel regulatory sequences compatible with modular assembly in the diatom Phaeodactylum tricornutum Phaeodactylum tricornutum ; Promoter ; Biology ; Terminator (solar) ; Gene expression ; Gene ; Computational biology ; Reporter gene ; Synthetic biology ; Genetics ; Diatom ; Botany Diatoms and Algae Research ; Algal biology and biofuel production ; Microbial Community Ecology and Physiology
Authors: Lidija Fras Zemljič | Uroš Maver | Tjaša Kraševac Glaser | Urban Bren | Maša Knez Hrnčič | Gabrijela Petek | Zdenka Peršin
Source: Materials (article, 2020-06-09)
Field: Materials Science — Biomaterials

Electrospun Composite Nanofibrous Materials Based on (Poly)-Phenol-Polysaccharide Formulations for Potential Wound Treatment In this paper, we focus on the preparation of electrospun composite nanofibrous materials based on (poly)-phenol-polysaccharide formulation. The prepared composite nanofibres are ideally suited as a controlled drug delivery system, especially for local treatment of different wounds, owing to their high surface and volume porosity and small fibre diameter. To evaluate the formulations, catechin and resveratrol were used as antioxidants. Both substances were embedded into chitosan particles, and further subjected to electrospinning. Formulations were characterized by determination of the particle size, encapsulation efficiency, as well as antioxidant and antimicrobial properties. The electrospinning process was optimised through fine-tuning of the electrospinning solution and the electrospinning parameters. Scanning electron microscopy was used to evaluate the (nano)fibrous structure, while the successful incorporation of bio substances was assessed by X-ray Photoelectron Spectroscopy and Fourier transform infrared spectroscopy. The bioactive properties of the formed nanofibre -mats were evaluated by measuring the antioxidative efficiency and antimicrobial properties, followed by in vitro substance release tests. The prepared materials are bioactive, have antimicrobial and antioxidative properties and at the same time allow the release of the incorporated substances, which assures a promising use in medical applications, especially in wound care. Electrospinning ; Materials science ; Fourier transform infrared spectroscopy ; Composite number ; Chemical engineering ; Porosity ; Chitosan ; Scanning electron microscope ; Composite material ; Polymer Electrospun Nanofibers in Biomedical Applications ; Silk-based biomaterials and applications ; Wound Healing and Treatments