jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hon Fai Wong | Sheung Mei Ng | Wen Zhang | Yukuai Liu | Ping Kwan Johnny Wong | Chi Sin Tang | Ka Kin Lam | Xu Wen Zhao | Zhen Meng | Linfeng Fei | Wang Fai Cheng | D. von Nordheim | Wai‐Yeung Wong | Zong Rong Wang | B. Ploss | Jiyan Dai | Chee Leung Mak | Andrew T. S. Wee | Chi Wah Leung
Source: ACS Applied Materials & Interfaces (article, 2020-12-06)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Modulating Magnetism in Ferroelectric Polymer-Gated Perovskite Manganite Films with Moderate Gate Pulse Chains Most previous attempts on achieving electric-field manipulation of ferromagnetism in complex oxides, such as La<sub>0.66</sub>Sr<sub>0.33</sub>MnO<sub>3</sub> (LSMO), are based on electrostatically induced charge carrier changes through high-<i>k</i> dielectrics or ferroelectrics. Here, the use of a ferroelectric copolymer, polyvinylidene fluoride with trifluoroethylene [P(VDF-TrFE)], as a gate dielectric to successfully modulate the ferromagnetism of the LSMO thin film in a field-effect device geometry is demonstrated. Specifically, through the application of low-voltage pulse chains inadequate to switch the electric dipoles of the copolymer, enhanced tunability of the oxide magnetic response is obtained, compared to that induced by ferroelectric polarization. Such observations have been attributed to electric field-induced oxygen vacancy accumulation/depletion in the LSMO layer upon the application of pulse chains, which is supported by surface-sensitive-characterization techniques, including X-ray photoelectron spectroscopy and X-ray magnetic circular dichroism. These techniques not only unveil the electrochemical nature of the mechanism but also establish a direct correlation between the oxygen vacancies created and subsequent changes to the valence states of Mn ions in LSMO. These demonstrations based on the pulsing strategy can be a viable route equally applicable to other functional oxides for the construction of electric field-controlled magnetic devices. Materials science ; Ferroelectricity ; Magnetism ; Dielectric ; Electric field ; Ferromagnetism ; Thin film ; Optoelectronics ; Condensed matter physics ; Nanotechnology Magnetic and transport properties of perovskites and related materials ; Multiferroics and related materials ; Perovskite Materials and Applications
Authors: Ahmed Abdel Khalek | Reham A. Mohamed | Mahmoud M. Abdel- Hafeez | Engy H. Gabrail
Source: International Journal of Engineering Research and Technology (article, 2020-04-30)
Field: Chemistry — Analytical Chemistry

Surface and Intraparticle Diffusion of Crystal Violet Dye on Egyptian Doum Fruit from Aqueous Solutions The adsorption of crystal violet (CV) dye from waste solution onto Doum Fruit (DF) using batch adsorption technique was investigated as a function of parameters such as initial pH, contact time, initial dye concentration, adsorbent amount, agitation speed and temperature. The DF was shown to be effective adsorbent for the removal of CV dye, and the equilibrium was reached in about 60 min. The experimental data were analyzed by Langmuir, Freundlich and Dubinin-Radushkevich isotherm models using linear regression analysis. The results of dsorption experiments indicate that the maximum sorption capacity (Qmax) of CV is 35.26 mg/g. Thermodynamic parameters such as G, H and S were also evaluated, the sorption process was found to be spontaneous and exothermic. The kinetic experimental data was analyzed using three kinetic models including pseudofirst order, pseudo-second order and intraparticle diffusion model to examine the mechanism of adsorption and potential rate-controlling step. The results indicated that the DF could be used effectively to adsorb CV dye from aqueous solutions. Crystal violet ; Diffusion ; Aqueous solution ; Chemistry ; Chemical engineering ; Materials science ; Physical chemistry ; Biology ; Thermodynamics ; Physics ; Microbiology Dye analysis and toxicity ; Edible Oils Quality and Analysis
Authors: Marcos D. Fernández-Leyes | Santiago Giménez Reyes | Ezequiel Cuenca | Jhon F. Sánchez Morales | Hernán A. Ritacco
Source: Coatings (article, 2020-01-22)
Field: Chemistry — Organic Chemistry

Adsorption Kinetics of a Cationic Surfactant Bearing a Two-Charged Head at the Air-Water Interface We studied the dynamics of adsorption at the air-water interface of a cationic surfactant bearing two charges, Gemini 12-2-12, at concentrations below and above the critical micelle concentration (cmc). We used maximum bubble pressure and Wilhelmy plate techniques in order to access all time scales in the adsorption process. We found that the adsorption dynamics are controlled by diffusion at the initial stage of the adsorption process (milliseconds) and it is kinetically controlled by an electrostatic barrier (minute) approaching the equilibrium surfactant surface concentration. Between these two extremes, we found several relaxation phenomena, all following exponential decays with characteristic times spanning from one to hundreds of seconds. By means of time-resolved surface potential measurements, we show that these processes involve charge redistribution within the interfacial region. The surface tension data are analyzed and interpreted in the framework of the free energy approach. Pulmonary surfactant ; Adsorption ; Surface tension ; Kinetics ; Maximum bubble pressure method ; Bubble ; Wilhelmy plate ; Chemistry ; Cationic polymerization ; Diffusion ; Gibbs isotherm ; Critical micelle concentration ; Relaxation (psychology) ; Thermodynamics ; Chemical physics ; Micelle ; Materials science ; Physical chemistry ; Aqueous solution ; Mechanics ; Polymer chemistry Surfactants and Colloidal Systems ; Electrostatics and Colloid Interactions ; Spectroscopy and Quantum Chemical Studies
Authors: Xinyu Zhang | Xiaopo Cheng | Monika Jansohn | Matthias Niedermaier | Thomas J. Lenk | Stefan Britting | Karsten Schmidt | Richard M. Laine
Source: Journal of the American Ceramic Society (article, 2020-11-09)
Field: Materials Science — Ceramics and Composites

<i>t</i> ‐ZrO <sub>2</sub> toughened Al <sub>2</sub> O <sub>3</sub> free‐standing films and as oxidation mitigating thin films on silicon nitride via colloidal processing of flame made nanopowders (NPs) Abstract Zirconia toughened aluminas (ZTAs) are one of the most important engineering ceramics with high melting points, excellent mechanical strength, and chemical stability, and are commonly used as wear resistant and high‐temperature components, as prosthetic implants, and electric circuit substrates. In this work, we explore methods of processing fine‐grained, dense, thin, free‐standing (ZrO 2 ) x (Al 2 O 3 ) 1− x films ( x = 0‐50 mol%, ~40 μm thick) by sintering flame made nanopowders (NPs) to optimize the t ‐ZrO 2 content, sinterability, and microstructures under select conditions (1120°C‐1500°C/5 h in O 2 or 95%N 2 /5%H 2 ). In all cases, the final sintered products retain t‐ ZrO 2 with average grain sizes (AGSs) of 0.1‐1 μm. ZTA film thicknesses were increased to ~200 μm to assess potential as electronic substrates. Excellent fracture toughness (24 MPa m 1/2 ) and small AGSs of 0.7 μm were found for ~200 μm thick ZTA films sintered at 1500°C/5 h/N 2 /H 2 using a three‐step binder burnout process. Furthermore, we show that homogeneous ZTA thin films (&lt;5 μm thick) can be sintered on Si 3 N 4 substrates (thickness ≈ 300 μm) to provide physical protection against oxidation under extreme conditions (1500°C/1 h/O 2 ), offering additional practical utility for high‐temperature ceramics and power electronic substrates. Materials science ; Sintering ; Ceramic ; Fracture toughness ; Microstructure ; Silicon nitride ; Composite material ; Thin film ; Nitride ; Cubic zirconia ; Grain size ; Silicon ; Nanotechnology ; Metallurgy Advanced ceramic materials synthesis ; Ferroelectric and Piezoelectric Materials ; Bone Tissue Engineering Materials
Authors: Enrique Martínez | Frédéric Soisson | Maylise Nastar
Source: Journal of Nuclear Materials (article, 2020-06-22)
Field: Materials Science — Materials Chemistry

Point defect evolution under irradiation: Finite size effects and spatio-temporal correlations Kinetic Monte Carlo ; Crystallographic defect ; Vacancy defect ; Monte Carlo method ; Statistical physics ; Recombination ; Diffusion ; Physics ; Materials science ; Molecular physics ; Condensed matter physics ; Chemistry ; Thermodynamics ; Mathematics ; Statistics Nuclear Materials and Properties ; Semiconductor materials and devices ; Fusion materials and technologies
Authors: Yi Zhou | Zhong Xiao | Shichao Liu | Ping Chen | Hua Pang | Yong Xin | Yongjun Jiao | Shixin Gao | Kun Zhang | Wenjie Li | Junchong Yu
Source: Computation (article, 2020-02-21)
Field: Materials Science — Materials Chemistry

Effect of Structure on the Thermal-Mechanical Performance of Fully Ceramic Microencapsulated Fuel The effect of non-fuel part size on the thermal-mechanical performance of fully ceramic microencapsulated (FCMTM) Fuel was investigated, and the non-fuel part size was selected according to integrity maintaining of non-fuel part and silicon carbide (SiC) layers. The non-fuel part size can affect the FCMTM temperature and stress distribution greatly by changing the distance between tristructural isotropic (TRISO) particles. The maximum temperature of SiC matrix increased from 1220 K to 1450 K with the non-fuel part size increasing from 100 μm to 500 μm, and the matrix temperature of all the samples was lower than the decomposition point of SiC ceramics. The maximum hoop stress decreased with non-fuel part size, but the inner part exhibiteda crosscurrent trend. The inner part of the SiC matrix lost structure integrity because of the large hoop stress caused by the deformation of TRISO particles, however, the non-fuel parts of FCMTM pellet may maintain their integrity when the non-fuel part size was larger than 300 μm. SiC layers hoop stress increased with non-fuel part size, and the failure probability of SiC layer was lower than 2.2 × 10−4 for the FCMTM pellet with small non-fuel part size. The integrity of non-fuel and SiC layers can be maintained for the FCMTM pellet with the non-fuel part size from 300 μm to 400 μm. Materials science ; Silicon carbide ; Ceramic ; Pellet ; Composite material ; Stress (linguistics) ; Ceramic matrix composite ; Cylinder stress ; Deformation (meteorology) ; Ultimate tensile strength Nuclear Materials and Properties ; Advanced ceramic materials synthesis ; Advanced materials and composites
Authors: Chaeyoung Lee | Hyun‐Dong Kim | Sungha Yoon Sungha Yoon | Jintae Park Jintae Park | Sangkwon Kim | Junxiang Yang | Junseok Kim
Source: Numerical Mathematics Theory Methods and Applications (article, 2020-10-08)
Field: Materials Science — Materials Chemistry

On the Evolutionary Dynamics of the Cahn-Hilliard Equation with Cut-Off Mass Source We investigate the effect of cut-off logistic source on evolutionary dynamics of a generalized Cahn-Hilliard (CH) equation in this paper. It is a well-known fact that the maximum principle does not hold for the CH equation. Therefore, a generalized CH equation with logistic source may cause the negative concentration blow-up problem in finite time. To overcome this drawback, we propose the cut-off logistic source such that only the positive value greater than a given critical concentration can grow. We consider the temporal profiles of numerical results in the one-, two-, and three-dimensional spaces to examine the effect of extra mass source. Numerical solutions are obtained using a finite difference multigrid solver. Moreover, we perform numerical tests for tumor growth simulation, which is a typical application of generalized CH equations in biology. We apply the proposed cut-off logistic source term and have good results. Logistic function ; Solver ; Applied mathematics ; Mathematics ; Dynamics (music) ; Cahn–Hilliard equation ; Multigrid method ; Partial differential equation ; Mathematical analysis ; Mathematical optimization ; Physics ; Statistics Solidification and crystal growth phenomena ; Fluid Dynamics and Thin Films ; Nonlinear Dynamics and Pattern Formation
Authors: X. F. Wang | B. Herman | Brad Chazotte | Gerald W. Gordon
Source: UNC Libraries (article, 2020-10-31)
Field: Chemistry — Spectroscopy

Analysis of simulated and experimental fluorescence recovery after photobleaching. Data for two diffusing components Fluorescence recovery after photobleaching has been a popular technique to quantify the lateral mobility of membrane components. A variety of analysis methods have been used to determine the lateral diffusional mobility, D. However, many of these methods suffer from the drawbacks that they are not able to discern two-component diffusion (i.e., three-point fit), cannot solve for two components (linearization procedures), and do not perform well at low signal-to-noise. To overcome these limitations, we have adopted the approach of fitting fluorescence recovery after photobleaching curves by the full series solution using a Marquardt algorithm. Using simulated data of one or two diffusing components, determinations of the accuracy and reliability of the method with regard to extraction of diffusion parameters and the differentiation of one- versus two-component recovery curves were made under a variety of conditions comparable with those found in actual experimental situations. The performance of the method was also examined in experiments on artificial liposomes and fibroblast membranes labeled with fluorescent lipid and/or protein components. Our results indicate that: 1) the method was capable of extracting one- and two-component D values over a large range of conditions; 2) the D of a one-component recovery can be measured to within 10% with a small signal (100 prebleach photon counts per channel); 3) a two-component recovery requires more than 100-fold greater signal level than a one-component recovery for the same error; and 4) for two-component fits, multiple recovery curves may be needed to provide adequate signal to achieve the desired level of confidence in the fitted parameters and in the differentiation of one- and two-component diffusion. Photobleaching ; Fluorescence recovery after photobleaching ; Fluorescence ; Biological system ; Biophysics ; Chemistry ; Materials science ; Optics ; Physics ; Biology Spectroscopy and Laser Applications ; Water Quality Monitoring and Analysis ; Spectroscopy and Chemometric Analyses
Authors: E. Salloum | O. Maloberti | M. Nesser | S. Panier | Julien Dupuy
Source: Journal of Magnetism and Magnetic Materials (article, 2020-02-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Identification and analysis of static and dynamic magnetization behavior sensitive to surface laser treatments within the electromagnetic field diffusion inside GO SiFe electrical steels Materials science ; Magnetostatics ; Magnetic field ; Electrical steel ; Mesoscopic physics ; Magnetization ; Laser ; Magnetic domain ; Magnetic flux ; Mechanics ; Optics ; Physics ; Condensed matter physics ; Composite material Magnetic Properties and Applications ; Magnetic properties of thin films ; Non-Destructive Testing Techniques
Authors: Ainaz Abildina | Akmaral Argimbayeva | Andrey Kurbatov | Yeldana Bakhytzhan | Gulmira Rakhymbay | Michael Wark | Patrick Bottke
Source: Applied Sciences (article, 2020-02-19)
Field: Materials Science — Biomaterials

Study of Polarization Characteristics of Corrosion Films on Magnesium in Sulfate-Containing Electrolytes In this article, the results of studying the polarization characteristics of magnesium covered with corrosion film in aqueous solutions of MgSO4 and Na2SO4 are presented. The absence of a corrosion-free magnesium surface was shown; in this connection, it was proposed to interpret the larger values of Tafel’s coefficients obtained in the experiment from the point of view of limiting the electrochemical process by charge transfer in the film phase. Charge transfer in corrosion films obeys the regularities of particle movement in high electric fields, and it is not only cationic. According to the impedance measurements, the resistance of the oxide and hydroxide layer of the magnesium-based corrosion film in the studied solutions was calculated. The largest contribution to the restriction of charge transfer in the initial stages of corrosion is made by a dense primary film defining the polarization resistance. Correlation of transfer parameters in high electric fields with thickness and resistance of corrosion film was demonstrated. Corrosion ; Materials science ; Tafel equation ; Polarization (electrochemistry) ; Magnesium ; Electrolyte ; Oxide ; Metallurgy ; Electrochemistry ; Electrode ; Chemistry ; Physical chemistry Magnesium Alloys: Properties and Applications ; Corrosion Behavior and Inhibition ; Magnesium Oxide Properties and Applications
Authors: Dieter Rehder
Source: Advances in Chemical Research (article, 2020-01-08)
Field: Chemistry — Inorganic Chemistry

Vanadium: Biological, Environmental, and Engineering Aspects Vanadium is an element that is widely distributed in Earth’s crust as well as in sea-water and ground-water reservoirs. Therefore, it exerts a great influence on the issues related to life and environment. Vanadium is utilized by several marine organisms. For example, there are vanadate-dependent haloperoxidases in algae and several bacteria, e.g., Azotobacter, use it for nitrogen fixation and bacterial reduction involves the conversion of vanadate to oxidovanadium (IV). The similarity between vanadate and phosphate imparts a physiological functional role to vanadate (V), and consequently, several aspects of medicinal potential to vanadate and vanadium coordination compounds, such as their use in the treatment of diabetes, cancer, and cardiovascular problems, which may be explained in conjunction with vanadate/phosphate antagonism. Similar considerations apply to the efficacy of vanadium compounds in the treatment of HIV and [tropical] diseases caused by bacteria and protozoa. In addition to this biological efficacy, vanadium plays an increasingly recognized role in industrial processes, such as steel production, oxidation catalysis, and vanadium-based energy storage (batteries) and solar cells. Vanadate ; Vanadium ; Phosphate ; Chemistry ; Environmental chemistry ; Inorganic chemistry ; Biochemistry Vanadium and Halogenation Chemistry ; Heme Oxygenase-1 and Carbon Monoxide ; Metal-Catalyzed Oxygenation Mechanisms
Authors: Alaa El-Din A. Gawad | Ahmed M. Bayoumy | Medhat Ibrahim
Source:  (preprint, 2020-07-09)
Field: Materials Science — Materials Chemistry

Molecular Interactions of Fullerene-Based Derivatives and SARS-CoV-2 <title>Abstract</title> There are no expedient proven to stop the outbreak of SARS-CoV-2 at this phase. This leads to diversity of endeavors to find out the effective drug or vaccine. One of these possibilities is to exploit the unique characteristics of fullerene-based derivatives. A computer-aided method (molecular docking) was applied to assess the differential binding behavior of these compounds and determining hydrophobic forces, electrostatic interactions, and hydrogen bonds played vital roles in the interactions with SARS-CoV-2 spike protein. The molecular docking calculation clarifies the binding mode and the binding sites may facilitate the development of new or improved therapeutic regimes effective against COVID-19. Fulleropyrrolidine-NH2 seems to be promising candidate for interacting with SARS-CoV-2 binding site. Fullerene ; Coronavirus disease 2019 (COVID-19) ; Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ; 2019-20 coronavirus outbreak ; Chemistry ; Virology ; Medicine ; Organic chemistry Carbon Nanotubes in Composites ; Fullerene Chemistry and Applications ; Nanotechnology research and applications
Authors: Camelia Elena Stecoza
Source: FARMACIA (article, 2020-12-21)
Field: Chemistry — Organic Chemistry

SYNTHESIS AND EVALUATION OF THE ANTIMICROBIAL AND ANTIBIOFILM ACTIVITY OF NOVEL DIBENZOTHIEPINES Considering the anti-infective potential of compounds containing the dibenzothiepine scaffold, we set out to obtain new compounds bearing this structure. The synthesized compounds were characterized by spectral studies and elemental analysis and screened for their microbiostatic/microbicidal and antibiofilm properties against reference and clinical microbial strains. The new compounds exhibited a broad spectrum of antimicrobial activity, which was more intensive for the S-oxidized compounds. Some of the compounds also inhibited the ability of the investigated strains to form biofilms on the inert substratum. Antimicrobial ; Microbiology ; Chemistry ; Biology Synthesis of β-Lactam Compounds ; Phenothiazines and Benzothiazines Synthesis and Activities ; Synthesis and biological activity
Authors: Marcus Henrique de Araujo | Túlio Matencio | Cláudio Luis Donnici | Hállen D. R. Calado
Source: Polímeros (article, 2020-01-01)
Field: Materials Science — Polymers and Plastics

Electrical and spectroelectrochemical investigation of thiophene-based donor-acceptor copolymers with 3,4-ethylenedioxythiophene This work reports the spectroelectrochemical and electrical behavior of electropolymerized donor-acceptor like (D-A) copolymer films, based on 3,4-ethylenedioxythiophene (EDOT) and beta-substituted electron-acceptor thiophenes. Initially, the copolymer films were deposited on indium tin oxide substrates, which spectroelectrochemistry measurements were carried out with an UV-Vis spectrophotometer. Hence, it was possible to observe the electrochromic properties of these materials, visualizing the color changing towards different potentials applied. The experiments have shown that these D-A like copolymers presented good electrochromic properties, such as optical contrast, coloration efficiency, and switching times. Additionally, films prepared on a platinum working electrode were investigated by electrochemical impedance spectroscopy, which has shown the electrical behavior of those copolymers and their potential as candidates to capacitive devices building. Therefore, the combination of electron-donor EDOT with those electron-acceptor monomers is indeed a useful strategy to tailoring and fine-tuning the physicochemical properties of polythiophenes with innovative applications. Electrochromism ; Materials science ; Copolymer ; Thiophene ; Acceptor ; Indium tin oxide ; Electron acceptor ; Electrochromic devices ; Monomer ; Dielectric spectroscopy ; Conductive polymer ; Photochemistry ; Chemical engineering ; Electrochemistry ; Polymer chemistry ; Optoelectronics ; Electrode ; Polymer ; Nanotechnology ; Thin film ; Organic chemistry ; Chemistry ; Physical chemistry ; Composite material Conducting polymers and applications ; Transition Metal Oxide Nanomaterials ; Organic Electronics and Photovoltaics