jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Han Jia | Wenjia Chen | Aihua Yu | Jianxin Yi
Source: Frontiers in Materials (article, 2019-10-04)
Field: Materials Science — Materials Chemistry

Detection of Semi-volatile Plasticizers as a Signature of Early Electrical Fire Detection of characteristic species released from over-heated PVC cables may enable early warning of electrical fires. This work identified the major volatile species for over-heated PVC cables, and verified their potential as fire signatures with metal oxide gas sensors. Semi-volatile Dioctyl phthalate (DOP) and 2-Ethylhexanol (2-EH) were found to be ubiquitously present in the cable vapors as major species. Detection of these species and the vapors of overheated cables was accomplished with a metal oxide gas sensor. The response of the gas sensor to the cable vapors resulted mainly from DOP and 2-EH, demonstrating them as effective signature gases for over-heated PVC cables. A gas sensor based on SnO2 nanofibers was prepared with greatly enhanced response to the signature gases. Large-scale simulation tests showed that the nanofiber gas sensor could effectively detect the cable overheating at an early stage. Overheating (electricity) ; Materials science ; Oxide ; Volatile organic compound ; Plasticizer ; Environmental science ; Composite material ; Environmental chemistry ; Chemistry ; Organic chemistry ; Electrical engineering High voltage insulation and dielectric phenomena ; Fire Detection and Safety Systems ; Electrical Fault Detection and Protection
Authors: Yung Suk Jeremy Yoo | Hojun Lim | John M Emery | Josh Kacher
Source: Acta Materialia (article, 2019-05-20)
Field: Materials Science — Materials Chemistry

Relating microstructure to defect behavior in AA6061 using a combined computational and multiscale electron microscopy approach Materials science ; Intermetallic ; Microstructure ; Grain boundary ; Dislocation ; Transmission electron microscopy ; Electron backscatter diffraction ; Scanning electron microscope ; Composite material ; Crystallography ; Metallurgy ; Nanotechnology ; Chemistry Microstructure and mechanical properties ; Aluminum Alloy Microstructure Properties ; Aluminum Alloys Composites Properties
Authors: Carlos León | Marcio Costa | Leonor Chico | A. Latgé
Source: Scientific Reports (article, 2019-03-05)
Field: Materials Science — Materials Chemistry

Interface effects in hybrid hBN-graphene nanoribbons We analyze the electronic properties of a hybrid graphene-BN nanoribbon system, using a Hubbard model Hamiltonian within a mean field approximation. Due to the different electronegativities of the boron and nitrogen atoms, an electric field is induced across the zigzag graphene strip, breaking the spin degeneracy of the electronic band structure. Optimal tight-binding parameters are found from first-principles calculations. Edge potentials are proposed as corrections for the on-site energies, modeling the BN-graphene nanoribbon interfaces. We show that half-metallic responses in the hybrid systems may be driven with the help of an external electric field. We also study the role of defects across the graphene nanoribbon and at the h-BN/graphene interface regions. Modulations on the spin-dependent gaps may be achieved depending on the nature and position of the defect, constituting a way towards spin-gap engineering by means of spatial doping. Graphene ; Zigzag ; Condensed matter physics ; Materials science ; Electric field ; Graphene nanoribbons ; Band gap ; Hamiltonian (control theory) ; Electronic structure ; Doping ; Nanotechnology ; Physics ; Quantum mechanics Graphene research and applications ; Quantum and electron transport phenomena ; Boron and Carbon Nanomaterials Research
Authors: MN Uddin | Ahamadunnabi Mondol | MM Karim | RA Jahan | AA Rana
Source: Bangladesh Journal of Scientific and Industrial Research (article, 2019-08-19)
Field: Chemistry — Analytical Chemistry

Chemometrics assisted spectrophotometric method for simultaneous determination of paracetamol and caffeine in pharmaceutical formulations In this study, two chemometric techniques, partial least-square regression (PLSR) and artificial neural network (ANN) were developed and compared for the simultaneous assay of paracetamol (PCT) and caffeine (CAF) in pharmaceutical formulations by using spectrophotometric data. Six different concentrations of paracetamol and caffeine were considered to make mixture solutions of standard samples by using orthogonal experimental design (OED). UV spectra of these mixtures were recorded in the wavelength range of 205-300 nm versus a solvent blank and digitized absorbance was sampled at 1 nm intervals. Drug concentrations and instrumental spectra of 36 mixture solutions were used for model development and validation and finally 6 commercially available tablets were used to test the developed models. ANN shows better prediction efficiencies than that of PLSR with R2 value 99.28% for prediction and 99.13% for validation set. These two models were successfully applied to commercial pharmaceutical formulations, and it is found by ANN that the drugs contain 75 to 86% of paracetamol and 77 to 92% of caffeine of their label claim. Either of the proposed methods is simple and rapid and can be easily used in the quality assessment of drugs as an alternative analytical method. Bangladesh J. Sci. Ind. Res.54(3), 215-222, 2019 Chemometrics ; Caffeine ; Chromatography ; Absorbance ; Partial least squares regression ; Chemistry ; Pharmaceutical formulation ; Analytical Chemistry (journal) ; Mathematics ; Statistics Analytical Methods in Pharmaceuticals ; Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies
Authors: Jianguo Wang | Yanjun Xi | Chunhua Fang | Li Cai | Jianping Wang | Yadong Fan
Source: IEEE Access (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Leakage Current Response Mechanism of Insulator String With Ambient Humidity on Days Without Rain The leakage current, which is influenced by the operating voltage, the surface contamination, and environmental variables, is one of the most basic online monitoring parameters for the surface contamination status of insulators. However, the impact of temperature and humidity on leakage current have not been expressed concisely nor distinguished according to sunny and rainy weather. In this paper, based on leakage current online monitoring data, the time-domain waveforms of leakage current of an insulator string in Shenzhen, China, were compared with those of the ambient temperature and humidity. Results indicate that the leakage current presents a saddle-shaped curve on days without rain, and that there is a remarkable positive correlation between leakage current and humidity as well as a negative correlation between leakage current and temperature. In a short period (several days) without rain, as long as the relative humidity keeps constant, the leakage current would vary insignificantly, whereas it may vary in a wide range at the same temperature. Moreover, the functional relation mathematical model I = a * e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b*RH</sup> between the first harmonic component of leakage current and the relative humidity is presented, inferring that the insulator string leakage current depends mainly on the ambient relative humidity in a day without rain. Relative humidity ; Humidity ; Leakage (economics) ; Insulator (electricity) ; Environmental science ; Contamination ; Waveform ; Voltage ; Electrical engineering ; Materials science ; Meteorology ; Optoelectronics ; Physics ; Engineering High voltage insulation and dielectric phenomena ; Power Transformer Diagnostics and Insulation ; Water Systems and Optimization
Authors: Sunkyu Yu | Xianji Piao | Namkyoo Park
Source: Advanced Science (article, 2019-06-03)
Field: Chemistry — Spectroscopy

Neuromorphic Functions of Light in Parity‐Time‐Symmetric Systems As an elementary processor of neural networks, a neuron performs exotic dynamic functions, such as bifurcation, repetitive firing, and oscillation quenching. To achieve ultrafast neuromorphic signal processing, the realization of photonic equivalents to neuronal dynamic functions has attracted considerable attention. However, despite the nonconservative nature of neurons due to energy exchange between intra- and extra-cellular regions through ion channels, the critical role of non-Hermitian physics in the photonic analogy of a neuron has been neglected. Here, a neuromorphic non-Hermitian photonic system ruled by parity-time symmetry is presented. For a photonic platform that induces the competition between saturable gain and loss channels, dynamical phases are classified with respect to parity-time symmetry and stability. In each phase, unique oscillation quenching functions and nonreciprocal oscillations of light fields are revealed as photonic equivalents of neuronal dynamic functions. The proposed photonic system for neuronal functionalities will become a fundamental building block for light-based neural signal processing. Neuromorphic engineering ; Parity (physics) ; Computer science ; Physics ; Artificial intelligence ; Particle physics ; Artificial neural network Molecular spectroscopy and chirality ; Photoreceptor and optogenetics research ; Quantum Mechanics and Non-Hermitian Physics
Authors: Yan Chen | Jonathan T. Vu | Mitchell G. Thompson | William A. Sharpless | Leanne Jade G. Chan | Jennifer Gin | Jay D. Keasling | Paul D. Adams | Christopher J. Petzold
Source: PLoS ONE (article, 2019-02-14)
Field: Chemistry — Spectroscopy

A rapid methods development workflow for high-throughput quantitative proteomic applications Recent improvements in the speed and sensitivity of liquid chromatography-mass spectrometry systems have driven significant progress toward system-wide characterization of the proteome of many species. These efforts create large proteomic datasets that provide insight into biological processes and identify diagnostic proteins whose abundance changes significantly under different experimental conditions. Yet, these system-wide experiments are typically the starting point for hypothesis-driven, follow-up experiments to elucidate the extent of the phenomenon or the utility of the diagnostic marker, wherein many samples must be analyzed. Transitioning from a few discovery experiments to quantitative analyses on hundreds of samples requires significant resources both to develop sensitive and specific methods as well as analyze them in a high-throughput manner. To aid these efforts, we developed a workflow using data acquired from discovery proteomic experiments, retention time prediction, and standard-flow chromatography to rapidly develop targeted proteomic assays. We demonstrated this workflow by developing MRM assays to quantify proteins of multiple metabolic pathways from multiple microbes under different experimental conditions. With this workflow, one can also target peptides in scheduled/dynamic acquisition methods from a shotgun proteomic dataset downloaded from online repositories, validate with appropriate control samples or standard peptides, and begin analyzing hundreds of samples in only a few minutes. Workflow ; Proteome ; Computational biology ; Proteomics ; Computer science ; Shotgun proteomics ; Throughput ; Quantitative proteomics ; Data mining ; Bioinformatics ; Chemistry ; Biology ; Database Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies
Authors: Adam Polak | Fraser K. Coutts | Paul Murray | Stephen Marshall
Source: IET Image Processing (article, 2019-03-22)
Field: Chemistry — Analytical Chemistry

Use of hyperspectral imaging for cake moisture and hardness prediction Industrial baking of sponge cakes requires various quality indicators to be measured during production such as moisture content and sponge hardness. Existing techniques for measuring these properties require randomly selected sponges to be removed from the production line before samples are manually cut out of each sponge in a destructive way for testing. These samples are subsequently processed manually using dedicated analysers to measure moisture and texture properties in a lengthy process, which can take a skilled operator around 20 min to complete per sponge. In this study, the authors present a new, single sensor hyperspectral imaging approach, which has the potential to measure both sponge moisture content and hardness simultaneously. In the last decade, hyperspectral imaging systems have reduced in cost and size and, as a result, they are becoming widely used in a number of industries and research areas. Recently, there has been an increased use of this technology in the food industry and in food science applications and research. The application of this technology in the cake production environment, empowered by sophisticated signal and image processing techniques and prediction algorithms as presented in this study has the potential to provide on‐line, real‐time, stand‐off cake quality monitoring. Hyperspectral imaging ; Moisture ; Remote sensing ; Water content ; Environmental science ; Materials science ; Computer science ; Geology ; Composite material ; Geotechnical engineering Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Mineral Processing and Grinding
Authors: Zhijin Zhang | Shenghuan Yang | Xingliang Jiang | Xinhan Qiao | Yingzhu Xiang | Dongdong Zhang
Source: Energies (article, 2019-06-19)
Field: Materials Science — Materials Chemistry

DC Flashover Dynamic Model of Post Insulator under Non-Uniform Pollution between Windward and Leeward Sides Experience shows that under unidirectional wind or certain terrain, the surface of post insulators is non-uniformly polluted between windward and leeward sides, which affects the flashover characteristics. In this paper, a formulation of residual pollution layer resistance was proposed under this non-uniformity and a typical post insulator was taken as an example to analyze and calculate its residual resistance. The theoretical resistance was verified by numerical simulations using COMSOL Multiphysics. The proposed resistance formulation was then implemented in a DC flashover dynamic model to determine the flashover voltage (Ucal), which was validated by artificial flashover tests. Then the factors affecting DC flashover voltage were analyzed. Research results indicate that: the residual resistance formulation agrees well with simulation results, especially when the arc length exceeds 70% of the leakage distance. The good concordance between theoretical and experimental flashover voltages with most relative error within ±10%, validates the flashover model and its residual resistance formulation. Ucal gets impaired under this non-uniformity. The degree of reduction is related to salt deposit density ratio (m) of windward to leeward side and leeward side area proportion (k). Arc flash ; Insulator (electricity) ; Residual ; Multiphysics ; Voltage ; Mechanics ; Materials science ; Environmental science ; Structural engineering ; Engineering ; Composite material ; Electrical engineering ; Mathematics ; Physics ; Finite element method High voltage insulation and dielectric phenomena ; Power Transformer Diagnostics and Insulation ; Lightning and Electromagnetic Phenomena
Authors: Daipayan Sarkar | Peiyuan Kang | Steven O. Nielsen | Zhenpeng Qin
Source: ACS Nano (article, 2019-07-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Non-Arrhenius Reaction-Diffusion Kinetics for Protein Inactivation over a Large Temperature Range Understanding protein folding and unfolding has been a long-standing fundamental question and has important applications in manipulating protein activity in biological systems. Experimental investigations of protein unfolding have been predominately conducted by small temperature perturbations (e.g., temperature jump), while molecular simulations are limited to small time scales (microseconds) and high temperatures to observe unfolding. Thus, it remains unclear how fast a protein unfolds irreversibly and loses function (i.e., inactivation) across a large temperature range. In this work, using nanosecond pulsed heating of individual plasmonic nanoparticles to create precise localized heating, we examine the protein inactivation kinetics at extremely high temperatures. Connecting this with protein inactivation measurements at low temperatures, we observe that the kinetics of protein unfolding is less sensitive to temperature change at the higher temperatures, which significantly departs from the Arrhenius behavior extrapolated from low temperatures. To account for this effect, we propose a reaction-diffusion model that modifies the temperature-dependence of protein inactivation by introducing a diffusion limit. Analysis of the reaction-diffusion model provides general guidelines in the behavior of protein inactivation (reaction-limited, transition, diffusion-limited) across a large temperature range from physiological temperature to extremely high temperatures. We further demonstrate that the reaction-diffusion model is particularly useful for designing optimal operating conditions for protein photoinactivation. The experimentally validated reaction-diffusion kinetics of protein unfolding is an important step toward understanding protein-inactivation kinetics over a large temperature range. It has important applications including molecular hyperthermia and calls for future studies to examine this model for other protein molecules. Kinetics ; Temperature jump ; Arrhenius equation ; Diffusion ; Atmospheric temperature range ; Chemical physics ; Chemistry ; Protein folding ; Microsecond ; Chemical kinetics ; Range (aeronautics) ; Nanosecond ; Thermodynamics ; Biophysics ; Activation energy ; Materials science ; Physical chemistry ; Physics ; Biochemistry Gold and Silver Nanoparticles Synthesis and Applications ; Protein Interaction Studies and Fluorescence Analysis ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: José E. Mosquera | María L. Goñi | Raquel E. Martini | Nicolás A. Gañán
Source: Journal of CO2 Utilization (article, 2019-05-08)
Field: Materials Science — Polymers and Plastics

Supercritical carbon dioxide assisted impregnation of eugenol into polyamide fibers for application as a dental floss Supercritical carbon dioxide ; Eugenol ; Materials science ; Dental floss ; Supercritical fluid ; Composite material ; Ultimate tensile strength ; Fiber ; Scanning electron microscope ; Desorption ; Chemical engineering ; Chemistry ; Organic chemistry ; Dentistry ; Adsorption Polymer Foaming and Composites ; Injection Molding Process and Properties ; Dental materials and restorations
Authors: Fabien Nassoy | Mathieu Pinault | Jérémie Descarpentries | Thomas Vignal | Philippe Banet | Pierre‐Eugène Coulon | Thomas Goislard de Monsabert | Harald Hauf | Pierre‐Henri Aubert | Cécile Reynaud | Martine Mayne–L'Hermite
Source: Nanomaterials (article, 2019-11-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Single-Step Synthesis of Vertically Aligned Carbon Nanotube Forest on Aluminium Foils Vertically aligned carbon nanotube (VACNT) forests are promising for supercapacitor electrodes, but their industrialisation requires a large-scale cost-effective synthesis process suitable to commercial aluminium (Al) foils, namely by operating at a low temperature (<660 °C). We show that Aerosol-Assisted Catalytic Chemical Vapour Deposition (CCVD), a single-step roll-to-roll compatible process, can be optimised to meet this industrial requirement. With ferrocene as a catalyst precursor, acetylene as a carbon source and Ar/H<sub>2</sub> as a carrier gas, clean and dense forests of VACNTs of about 10 nm in diameter are obtained at 615 °C with a growth rate up to 5 µm/min. Such novel potentiality of this one-step CCVD process is at the state-of-the-art of the multi-step assisted CCVD processes. To produce thick samples, long synthesis durations are required, but growth saturation occurs that is not associated with a diffusion phenomenon of iron in aluminium substrate. Sequential syntheses show that the saturation trend fits a model of catalytic nanoparticle deactivation that can be limited by decreasing acetylene flow, thus obtaining sample thickness up to 200 µm. Cyclic voltammetry measurements on binder-free VACNT/Al electrodes show that the CNT surface is fully accessible to the ionic liquid electrolyte, even in these dense VACNT forests. Materials science ; Acetylene ; Carbon nanotube ; Chemical vapor deposition ; Chemical engineering ; Nanotechnology ; Catalysis ; Electrode ; Cyclic voltammetry ; Electrolyte ; Aluminium ; Nanoparticle ; Electrochemistry ; Composite material ; Organic chemistry ; Chemistry Supercapacitor Materials and Fabrication ; Carbon Nanotubes in Composites ; Graphene research and applications
Authors: Sean Harvey | Marco Raabe | Anna Ermakova | Yingke Wu | Todd Zapata | Chaojian Chen | Hao Lü | Fedor Jelezko | David Y. W. Ng | Tanja Weil
Source: Advanced Therapeutics (article, 2019-08-16)
Field: Materials Science — Materials Chemistry

Transferrin‐Coated Nanodiamond–Drug Conjugates for Milliwatt Photothermal Applications Abstract Fluorescent nanodiamonds (fNDs) are unique carbon‐based nanomaterials due to their outstanding optical and magnetic properties. However, realization of the full potential of fNDs is often limited by their processability because fNDs aggregate strongly in both organic and aqueous solutions. Therefore, robust and potentially universal coating strategies are urgently needed to address these limitations. Derived from mussel foot proteins, the polymerization of l ‐3,4‐dihydroxyphenylalanine ( l ‐DOPA) provides important surface functional groups including amines, carboxylic acid, alcohols, and conjugated Michael acceptors. Herein, l ‐DOPA is polymerized on fNDs with a high control over the shell thickness. Photoluminescence and optically detected magnetic resonance studies reveal that the unique photophysical properties of fNDs are preserved after thin poly( l ‐DOPA) film coating. Subsequently, conjugation of transferrin, a heme protein that provides efficient receptor‐specific cellular transport, improves the colloidal stability and cellular uptake of the poly( l ‐DOPA)‐coated fNDs. The loading of FDA‐approved indocyanine green as a photothermal agent yields an integrated biohybrid material exhibiting an amplified photothermal effect in cells at very low energy intake (≈90 mW cm −2 ). Photothermal therapy ; Bioconjugation ; Indocyanine green ; Polymerization ; Materials science ; Nanotechnology ; Chemistry ; Drug delivery ; Biophysics ; Polymer ; Organic chemistry Diamond and Carbon-based Materials Research ; Luminescence and Fluorescent Materials ; Laser-Ablation Synthesis of Nanoparticles