jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Nikola Slavković | Milan Bjelica
Source: Journal of Electronic Imaging (article, 2019-06-25)
Field: Chemistry — Analytical Chemistry

Risk prediction algorithm based on image texture extraction using mobile vehicle road scanning system as support for autonomous driving We present an algorithm for risk prediction of road surface grip where skidding and sliding occur as main road surface problems. Prediction is done by defining a fine texture classification of the properties of road aggregate. In an experimental setup, data acquisition is performed with a supervised mobile vehicle scanning system, using a vehicle equipped with a camera and temperature sensor during movement along an arterial road. Image processing is performed by testing four texture feature extraction methods: Gabor filters, wavelet transform, gray level co-occurence matrix, and edge histogram descriptor, among which the Gabor transform shows the best results. The extraction of texture feature vectors follows by statistical algorithms for measuring feature vector similarity and reference vector selection, leading to image texture classification. The algorithm itself is upgraded by incorporating simultaneous surface temperature measurements in order to create and validate the final fine surface texture classification. The roads are classified and segmented into high-, medium-, and low-risk roads according to skid danger, enabling the creation of a map of high-risk zones. We validate our risk prediction algorithm by referring to crash rate data from the Road Traffic Safety Agency of Serbia database. This algorithm enables the location and mapping of high-risk zones and can be used as a support for autonomous driving and navigation. Artificial intelligence ; Computer science ; Road surface ; Feature extraction ; Computer vision ; Support vector machine ; Wavelet transform ; Histogram ; Image texture ; Pattern recognition (psychology) ; Segmentation ; Image segmentation ; Wavelet ; Engineering ; Image (mathematics) Spectroscopy and Chemometric Analyses ; Remote Sensing and LiDAR Applications ; Smart Agriculture and AI
Authors: Jason J. Maldonis | Zhongnan Xu | Zhewen Song | Min Yu | Tam Mayeshiba | Dane Morgan | Paul M. Voyles
Source: Computational Materials Science (article, 2019-01-02)
Field: Materials Science — Materials Chemistry

StructOpt: A modular materials structure optimization suite incorporating experimental data and simulated energies Modular design ; Computer science ; Suite ; Particle swarm optimization ; Interface (matter) ; Computational science ; Data structure ; Code (set theory) ; Energy (signal processing) ; Algorithm ; Parallel computing ; Programming language ; Physics Machine Learning in Materials Science ; Catalytic Processes in Materials Science ; Semiconductor materials and devices
Authors: Camille Bilodeau | Edmond Y. Lau | Steven M. Cramer | Shekhar Garde
Source: The Journal of Physical Chemistry B (article, 2019-05-22)
Field: Chemistry — Spectroscopy

Conformational Equilibria of Multimodal Chromatography Ligands in Water and Bound to Protein Surfaces Multimodal chromatography uses small ligands with multiple modes of interaction, e.g., charged, hydrophobic or hydrogen bonding, to separate proteins from complex mixtures. The mechanism by which multimodal ligands interact with proteins is expected to be affected by ligand conformations, among other factors. Here, we study conformational equilibria of two commercially used multimodal cation exchange ligands, Capto MMC and Nuvia cPrime, in a range of solvents, a Lennard-Jones (LJ) liquid, ethanol, and water, using molecular dynamics (MD) simulations. By mapping ligand conformations onto two key torsion angles, ω and φ, in these solvents and in low and high dielectric media, we quantify the relative importance of intramolecular and solvent-mediated interactions. In a high dielectric medium, Capto MMC preferentially samples three conformations, which are stabilized by a combination of an intramolecular torsion potential (on ω) and LJ interactions. In an LJ liquid, solvent molecules compete with intramolecular interactions while simultaneously providing an osmotic force, stabilizing both closer and farther distances between ligand sites. This has the overall effect of "flattening out" the conformational landscape. Interestingly, in ethanol and water, hydrogen bonding between the amide hydrogen and solvent molecules stabilizes two additional conformations of Capto MMC in which ω takes on less favorable cis-like configurations. MD simulations of ligands in free solution with three therapeutic antibody fragments show that ligand conformational equilibria remain effectively unchanged upon binding to proteins. Although, there is 20-30% dehydration of the overall ligand upon binding, the hydrogen-bonding sites are dehydrated to a much smaller extent, particularly in cis-like configurations. Conformational preferences of Nuvia cPrime are similar to that of Capto MMC, except for the effect of symmetry arising from the absence of an alkyl thiol tail. Characterizing the conformational equilibria of these two ligands in free solution and bound to a protein provides a foundation for developing a mechanistic understanding of protein-multimodal ligand interactions. Chemistry ; Chromatography Analytical Chemistry and Chromatography ; Protein purification and stability ; Protein Structure and Dynamics
Authors: Gregor N. C. Simm | José Miguel Hernández-Lobato
Source: arXiv (Cornell University) (preprint, 2019-09-25)
Field: Materials Science — Materials Chemistry

A Generative Model for Molecular Distance Geometry Great computational effort is invested in generating equilibrium states for molecular systems using, for example, Markov chain Monte Carlo. We present a probabilistic model that generates statistically independent samples for molecules from their graph representations. Our model learns a low-dimensional manifold that preserves the geometry of local atomic neighborhoods through a principled learning representation that is based on Euclidean distance geometry. In a new benchmark for molecular conformation generation, we show experimentally that our generative model achieves state-of-the-art accuracy. Finally, we show how to use our model as a proposal distribution in an importance sampling scheme to compute molecular properties. Euclidean geometry ; Probabilistic logic ; Benchmark (surveying) ; Markov chain Monte Carlo ; Generative model ; Markov chain ; Graph ; Computer science ; Representation (politics) ; Manifold (fluid mechanics) ; Statistical physics ; Algorithm ; Theoretical computer science ; Geometry ; Generative grammar ; Mathematics ; Artificial intelligence ; Machine learning ; Bayesian probability ; Physics Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Protein Structure and Dynamics
Authors: Karolina Fila | Yuliia Bolbukh | Marta Goliszek | Beata Podkościelna | Mateusz Gargol | Barbara Gawdzik
Source: Adsorption (article, 2019-02-14)
Field: Materials Science — Materials Chemistry

Synthesis and characterization of mesoporous polymeric microspheres of methacrylic derivatives of aromatic thiols The paper presents the synthesis and characterization of mesoporous microspheres of derivatives of three aromatic thiols: S-phenyl 2-methylprop-2-enethioate (PSM), S,S′-thiodi-4,1-phenylenebis(thiomethacrylate) (DMSPS), and bis[4(2-hydroxy-3-methacryloyloxypropoxy)phenyl]sulfide (BES.DM) with divinylbenzene (DVB). The microspheres were obtained by the emulsion-suspension polymerization procedure. The chemical and porous structure, morphology, and properties of the microspheres were analyzed by attenuated total reflection-Fourier transform infrared (ATR/FT-IR) spectroscopy, low-temperature nitrogen adsorption data, optical microscope MORPHOLOGI G3, differential scanning calorimetry (DSC), and wavelength dispersive X-ray fluorescence (WD-XRF). Moreover, studies on the Pb(II) ions sorption process were carried out on the above mentioned compounds. The sorption kinetics and mechanism were described by the pseudo-first order, pseudo-second order, and intraparticle diffusion models. The sorption equilibria were described by the Langmuir and Freundlich isotherms. The PSM-DVB, DMSPS-DVB, and BES.DM-DVB microspheres exhibit high thermal resistance and good adsorption properties of Pb(II) ions. The best adsorption properties for the examined microspheres were obtained at pH 5. The highest monolayer adsorption capacity determined by Langmuir isotherm was obtained for the DMSPS-DVB microspheres and was equal to 22.54 mg/g. The preliminary studies show that the synthesized microspheres can be used as heavy metal ion sorbents from aqueous solutions. Differential scanning calorimetry ; Adsorption ; Sorption ; Mesoporous material ; Langmuir ; Divinylbenzene ; Materials science ; Langmuir adsorption model ; Emulsion polymerization ; Freundlich equation ; Polymerization ; Chemical engineering ; Nuclear chemistry ; Chemistry ; Polymer chemistry ; Copolymer ; Styrene ; Organic chemistry ; Polymer Covalent Organic Framework Applications ; Conducting polymers and applications ; Adsorption and biosorption for pollutant removal
Authors: Zhoumin Qiu | Yuzhong Niu | Tiantian Fu | Ke Wang | Qiuhong Mu | Feng Wang
Source: Process Safety and Environmental Protection (article, 2019-02-10)
Field: Materials Science — Polymers and Plastics

Removal of Ni(II) from fuel ethanol by PAMAM dendrimers/silica hybrid materials: Combined experimental and theoretical study Ethanol ; Dendrimer ; Chemical engineering ; Materials science ; Chemistry ; Waste management ; Nuclear chemistry ; Organic chemistry ; Engineering Dendrimers and Hyperbranched Polymers ; Adsorption and biosorption for pollutant removal ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Toshihiko Hanai
Source: Separations (article, 2019-01-05)
Field: Chemistry — Spectroscopy

Fundamental Properties of Packing Materials for Liquid Chromatography The high performance of chemically-modified silica gel packing materials is based on the utilization of pure silica gels. Earlier silica gels used to be made from inorganic silica; however, nowadays, silica gels are made from organic silanes. The surface smoothness and lack of trace metals of new silica gels permits easy surface modifications (chemical reactions) and improves the reproducibility and stability. Sharpening peak symmetry is based on developing better surface modification methods (silylation). Typical examples can be found in the chromatography of amitriptyline for silanol testing and that of quinizarin for trace metal testing. These test compounds were selected and demonstrated sensitive results in the measurement of trace amounts of either silanol or trace metals. Here, we demonstrate the three-dimensional model chemical structures of bonded-phase silica gels with surface electron density for easy understanding of the molecular interaction sites with analytes. Furthermore, a quantitative explanation of hydrophilic and hydrophobic liquid chromatographies was provided. The synthesis methods of superficially porous silica gels and their modified products were introduced. Silanol ; Silica gel ; Silylation ; Chemistry ; Materials science ; Chromatography ; Silanes ; Surface modification ; Trace Amounts ; Hydrophobic silica ; Chemical engineering ; Organic chemistry ; Silane Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications ; Mass Spectrometry Techniques and Applications
Authors: Lin Yan | Guigan Fang | Yongjun Deng | Kuizhong Shen | Chen Huang | Ting Wu
Source: BioResources (article, 2019-05-29)
Field: Materials Science — Polymers and Plastics

A pH-sensitive xylan-based superabsorbent hydrogel for the removal of methylene blue from water A novel porous xylan-based hydrogel was prepared using methacrylated xylan and acrylic acid via free radical polymerization. The structure, morphology, and thermal stability of the hydrogel were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The pH value had an important effect on the swelling and dye-adsorption properties of the hydrogel. When methylene blue was used as a dye model, the dye adsorption of the hydrogel followed the Langmuir isotherm model and pseudo-second order kinetic model. The calculated maximum adsorption capacity reached 4720 mg/g. Besides, the hydrogel retained about 90% of its adsorptive capacity even after 4 cycles of usage. Therefore, the xylan-based hydrogel presented excellent dye adsorption performance and could be a promising superabsorbent for wastewater treatment. Thermogravimetric analysis ; Adsorption ; Methylene blue ; Materials science ; Langmuir adsorption model ; Fourier transform infrared spectroscopy ; Chemical engineering ; Superabsorbent polymer ; Self-healing hydrogels ; Acrylic acid ; Thermal stability ; Xylan ; Swelling ; Polymerization ; Acid dye ; Nuclear chemistry ; Polymer chemistry ; Chemistry ; Polymer ; Composite material ; Organic chemistry ; Dyeing ; Catalysis ; Cellulose Conducting polymers and applications ; Hydrogels: synthesis, properties, applications ; Adsorption and biosorption for pollutant removal
Authors: El Said A. Nouh | T.A. Lasheen | Rabab M. El‐Sherif | Nabil A. Abdel Ghany | E. A. Jebril
Source: SN Applied Sciences (article, 2019-01-14)
Field: Chemistry — Inorganic Chemistry

CeO2–TiFe2O4 nanocomposite for effective removal of uranium ions from aqueous waste solutions Adsorption ; Nanocomposite ; Endothermic process ; Sorbent ; Freundlich equation ; Aqueous solution ; Materials science ; Uranium ; Chemical engineering ; Cerium ; Nuclear chemistry ; Chemistry ; Nanotechnology ; Metallurgy ; Organic chemistry Radioactive element chemistry and processing ; Iron oxide chemistry and applications ; Extraction and Separation Processes
Authors: L. A. Yousef | A. R. Bakry | Ahmad A. Ahmad
Source: SN Applied Sciences (article, 2019-08-03)
Field: Chemistry — Inorganic Chemistry

Thorium ions recovery using activated carbon modified with triphenyl phosphine oxide: kinetic and equilibrium studies Adsorption ; Chemistry ; Phosphine oxide ; Thorium ; Activated carbon ; Sorption ; Nuclear chemistry ; Toluene ; Langmuir adsorption model ; Inorganic chemistry ; Phosphine ; Catalysis ; Physical chemistry ; Organic chemistry ; Materials science ; Metallurgy Radioactive element chemistry and processing ; Chemical Synthesis and Characterization ; Adsorption and biosorption for pollutant removal
Authors: Yifan Chen | Lei Ding | Bo Jiang | Li Liu | Yunzhe Du | Yudong Huang
Source: ES Materials & Manufacturing (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Excellent Gas Barrier Properties PET Film Modified by Silicone Resin/Sericite Nanocomposite Coatings In order to improve the gas barrier properties of PET films, the intercalated sericite was used as a barrier material in the functional silicone resin coatings. Firstly, the functional silicone resin with excellent thermal properties and high crosslinking degree was prepared. Secondly, lamellar sericite was intercalated and characterized by SEM and XRD. It was found that the lamellar spacing changed to 1.053 nm, and the compatibility in silicone resin was improved. Finally, the water vapor permeability (WVTR) and the oxygen permeability (OTR) of the 2 modified PET film were tested. The results showed that WVTR and OTR of the modified PET film reached 12.40 g/(m 24 h) and 29.91 3 2 Materials science ; Sericite ; Silicone ; Nanocomposite ; Composite material ; Lamellar structure ; Oxygen permeability ; Permeation ; Silicone resin ; Oxygen ; Membrane ; Chemistry ; Organic chemistry High voltage insulation and dielectric phenomena ; Synthesis and properties of polymers ; Silicone and Siloxane Chemistry
Authors: Yee Sin Ang | L. K. Ang
Source: Frontiers in Materials (article, 2019-08-27)
Field: Materials Science — Materials Chemistry

Theory of Thermionic Carrier Injection in Graphene/Organic Schottky Interface Understanding the physics of charge transport in organic materials and charge injection across organic-based interface is critically important for the development of novel organic electronics and optoelectronics. Despite extensive efforts devoted to the study of transport and injection phenomena in organic materials and interfaces, the physics of thermionic carrier injection across graphene/organic interface remains largely incomplete thus far. Here we construct a model of thermionic carrier injection across a graphene/organic Schottky interface based on the Lengevin theory of charge recombination and the detailed balance formalism. We show that, due to the strong electrostatic doping effect in graphene under the influence of an external gate voltage, the electrical current traversing the interface differs significantly from conventional bulk-metal/organic Schottky interface and the injection current can be efficiently modulated by a gate-voltage to achieve an on-off ratio well-exceed $10^7$. The model developed here shall provide a theoretical foundation for the understanding graphene/organic Schottky interface, thus paving the way towards the development of novel nanoscale graphene-hybrid organic electronic and optoelectronic devices. Thermionic emission ; Graphene ; Schottky diode ; Materials science ; Schottky barrier ; Charge carrier ; Organic semiconductor ; Optoelectronics ; Nanotechnology ; Electron ; Physics Graphene research and applications ; Molecular Junctions and Nanostructures ; Semiconductor materials and interfaces
Authors: Ankur Garg | Neelu Jain | Sanjeev Kumar | Shahrir R. Kasjoo | Arun Kumar Singh
Source: Nanoscale Advances (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Analysis of nonlinear characteristics of a graphene based four-terminal ballistic rectifier using a drift-diffusion model In this study, rectification behavior and noise spectra of a graphene based four-terminal ballistic rectifier are reported utilizing semi-classical drift-diffusion 3D modeling. The room temperature DC and RF characteristics of the novel rectifier are demonstrated considering the traps in the material similar to a real device, reducing the rectification efficiency from 0.5% to 0.35%. The responsivity and noise equivalent power of about 89.21 mV mW<sup>-1</sup> and 97.52 pW Hz<sup>-1/2</sup>, respectively, are obtained for different frequencies varying from 50 Hz to 1 THz. Furthermore, the noise spectral analysis of the device predicts a minimum low frequency noise, which depends upon the carrier concentration inside the device active region rather than mobility, and hence enables potential applications as THz detectors for imaging. Rectifier (neural networks) ; Graphene ; Nonlinear system ; Terminal (telecommunication) ; Diffusion ; Topology (electrical circuits) ; Physics ; Computer science ; Materials science ; Electrical engineering ; Nanotechnology ; Engineering ; Telecommunications ; Quantum mechanics ; Artificial intelligence Graphene research and applications ; Carbon Nanotubes in Composites ; Radiation Effects in Electronics
Authors: Luís Felipe dos Santos Carollo | Ana Silva | Sandro Metrevelle Marcondes de Lima e Silva
Source: Materials (article, 2019-08-13)
Field: Materials Science — Materials Chemistry

A Different Approach to Estimate Temperature-Dependent Thermal Properties of Metallic Materials Thermal conductivity, <i>λ</i>, and volumetric heat capacity, <i>ρc<sub>p</sub></i>, variables that depend on temperature were simultaneously estimated in a diverse technique applied to AISI 1045 and AISI 304 samples. Two distinctive intensities of heat flux were imposed to provide a more accurate simultaneous estimation in the same experiment. A constant heat flux was imposed on the upper surface of the sample while the temperature was measured on the opposite insulated surface. The sensitivity coefficients were analyzed to provide the thermal property estimation. The Broydon-Fletcher-Goldfarb-Shanno (BFGS) optimization technique was applied to minimize an objective function. The squared difference objective function of the numerical and experimental temperatures was defined considering the error generated by the contact resistance. The temperature was numerically calculated by using the finite difference method. In addition, the reliability of the results was assured by an uncertainty analysis. Results showing a difference lower than 7% were obtained for <i>λ</i> and <i>ρc<sub>p,</sub></i> and the uncertainty values were above 5%. Broyden–Fletcher–Goldfarb–Shanno algorithm ; Thermal conductivity ; Materials science ; Heat flux ; Thermal ; Thermal resistance ; Thermodynamics ; Function (biology) ; Finite difference method ; Finite difference ; Mechanics ; Mathematics ; Heat transfer ; Mathematical analysis ; Composite material ; Physics ; Computer science Thermal properties of materials ; Heat Transfer and Optimization ; Spacecraft and Cryogenic Technologies
Authors: Andrew Schlup | William J. Costakis | Wolfgang Rheinheimer | Rodney W. Trice | Jeffrey P. Youngblood
Source: Journal of the American Ceramic Society (article, 2019-11-27)
Field: Materials Science — Ceramics and Composites

Hot‐pressing platelet alumina to transparency Abstract Alumina powder with a platelet morphology was hot‐pressed to transparency with preload pressures of 0‐8 MPa, maximum temperatures of 1750‐1825°C, maximum pressures of 2.5‐80 MPa, and isothermal hold times of 1‐7 hours. Optical transmission (in‐line and total), as well as optical losses (backward/forward scattering and absorption), of the hot‐pressed samples were measured and related to the microstructure. Higher hot‐pressing temperatures increase the in‐line transmission. A gray discoloration of the samples (indicative of high absorption) was minimized by heat treating the powder in air prior to hot pressing and reducing the preload pressure. Maximum pressures above/below 10 MPa increased porosity, which decreased in‐line transmission and increased backward/forward scattering. Lower densities at higher pressures are attributed to a pore‐swelling phenomenon. Increasing isothermal hold time decreased porosity, which increased in‐line transmission and reduced backward/forward scattering. Best optical properties with an in‐line transmission of 65.3% at 645 nm (0.8 mm thick) were achieved by hot‐pressing heat‐treated platelet alumina powder with a preload pressure of 0 MPa, maximum temperature of 1800°C, maximum pressure of 10 MPa, and an isothermal hold time of 7 hours. This high in‐line transmission, despite its large grain size (65 µm), is attributed to crystallographic orientation of the platelets during hot pressing. Materials science ; Isothermal process ; Microstructure ; Porosity ; Composite material ; Hot pressing ; Pressing ; Sintering ; Grain size ; Metallurgy ; Thermodynamics Advanced ceramic materials synthesis ; Ferroelectric and Piezoelectric Materials ; Glass properties and applications