jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sophia Barınova | Toirbek Niyatbekov | S Barinova | T Niyatbekov | H Lange-Bertalot | D Metzeltin | M Guiry | G Guiry | J Love | R Selker | M Marsman | T Jamil | D Dropmann | A Verhagen | A Ly | Q Gronau | M Smira | S Epskamp | D Matzke | A Wild | J Rouder | R Morey | E Wagenmakers | A Jiyenbekov | A Bigaliev | S Nurashov | E Sametova | T Fahima | M Boboev | S Proulx | D Promislow | P Phillips | T Romanuk | R Vogt | A Young | C Tuck | M Carscallen | H Hisoriev | V Gabyshev | L Kukhaleishvili | O Bilous
Source: International Journal of Advanced Research in Botany (article, 2019-01-01)
Field: Materials Science — Biomaterials

Comparative Analysis of Diatom Algae Diversity in the Pamir Protected Lakes, Tajikistan Diatom algae from six Pamir lakes located at an altitude from 3,729 to 4,213 m above the sea level were studied in 466 samples collected in summer period of 2000-2018. Altogether 300 species of diatom algae (330 with infraspecies) of 76 genera were revealed in periphytonic 466. The richest communities were found in two freshwater lakes Turumtaykul with 171 species (184 taxa) and Rangkul with 162 species (176 taxa). Floristic analysis with help of statistical methods show that the water salinity can be regulating factor of diatom diversity development in high mountain lakes. The Pinnularia genus was the richest in five from six lakes floras. The two floristic core were revealed in the analysis of the species overlapping. The natural status of the protected high mountain lakes as a result of our analysis is indicates a high level of conservation of diversity in the territory of the Tajik National Park and the adjacent high-mountainous areas. Advanced statistical methods help us to characterize the stability of studied algal floras in protected high mountain lakes as higher on the genera level then on the species level, and therefore species of studied floras can be source of evolutionary speciation. Diatom ; Algae ; Diversity (politics) ; Geography ; Ecology ; Biology ; Anthropology ; Sociology Diatoms and Algae Research ; Aquatic Ecosystems and Phytoplankton Dynamics ; Aquatic Invertebrate Ecology and Behavior
Authors: Chaofeng Zhao | Jiaren Jin | Yingzhong Huo | Lu Sun | AI Yuejie
Source: Journal of Inorganic Materials (article, 2019-12-11)
Field: Materials Science — Materials Chemistry

Adsorption of Phenolic Organic Pollutants on Graphene Oxide: Molecular Dynamics Study 1 , 1 , 1 , 2 , 1 (1. , , 102206; 2. , 300350) : (Molecular dynamics simulation, MD), - 4-, (Phenolic Organic Pollutants, POPs)(Graphene Oxide, GO) POPs GO : 4-(41.34 kJ/mol)>-(33.23 kJ/mol)> (19.31 kJ/mol) POPs , Graphene ; Materials science ; Adsorption ; Pollutant ; Oxide ; Molecular dynamics ; Environmental chemistry ; Chemical engineering ; Nanotechnology ; Chemical physics ; Organic chemistry ; Computational chemistry ; Metallurgy ; Chemistry Carbon Nanotubes in Composites ; Graphene research and applications ; Adsorption and biosorption for pollutant removal
Authors: É. S. Mkrtchyan | A. E. Burakov | И. В. Буракова
Source: Materials Today Proceedings (article, 2019-01-01)
Field: Chemistry — Organic Chemistry

The Adsorption of Malachite Green on Graphene Nanocomposites: A Study on Kinetics Under Dynamic Conditions Graphene ; Adsorption ; Malachite green ; Materials science ; Chemical engineering ; Oxide ; Nanocomposite ; Kinetics ; Diffusion ; Chemistry ; Nanotechnology ; Organic chemistry ; Thermodynamics Nanomaterials for catalytic reactions ; Adsorption and biosorption for pollutant removal ; Graphene and Nanomaterials Applications
Authors: Dali Cai | Hao Xiong | Chenxi Zhang | Fei Wei
Source: Small (review, 2019-08-29)
Field: Chemistry — Inorganic Chemistry

Transport Phenomena in Zeolites in View of Graph Theory and Pseudo‐Phase Transition Transport phenomena play an essential role in catalysis. While zeolite catalysis is widely applied in industrial chemical processes, its efficiency is often limited by the transport rate in the micropores of the zeolite. Experimental and theoretical methods are useful for understanding the transport phenomena on multiscale levels. Traditional diffusion models usually use a linear driving force and an isotropic continuum medium, such that transport in a hierarchical catalyst structure and the occurrence of nonlinear deactivation cannot be well understood. Due to the presence of spatial confinement and an ordered structure, some aspects of the transport in a zeolite cannot be regarded as continuum phenomena and discrete models are being developed to explain these. Graph theory and small-world networks are powerful tools that have allowed pseudo-phase transition phenomena and other nontrivial relationships to be clearly revealed. Discrete models that include graph theory can build a bridge between microscopic quantum physics and macroscopic catalyst engineering in both the space and time scales. For a fuller understanding of transport phenomena in diverse fields, several theoretical methods need to be combined for a comprehensive multiscale analysis. Phase transition ; Transport phenomena ; Zeolite ; Statistical physics ; Isotropy ; Transition state theory ; Nonlinear system ; Graph theory ; Materials science ; Chemical physics ; Nanotechnology ; Physics ; Catalysis ; Chemistry ; Classical mechanics ; Mathematics ; Mechanics ; Quantum mechanics Zeolite Catalysis and Synthesis ; Spectroscopy and Quantum Chemical Studies ; Nanopore and Nanochannel Transport Studies
Authors: Erland-Modeste Kombaya-Touckia-Linin | Sébastien Gaucel | Moulay Tahar Sougrati | Lorenzo Stievano | Nathalie Gontard | Valérie Guillard
Source: Nanomaterials (article, 2019-08-23)
Field: Materials Science — Polymers and Plastics

Elaboration and Characterization of Active Films Containing Iron–Montmorillonite Nanocomposites for O2 Scavenging Iron particles of sizes between 6 and 20 nm forming aggregates of 57 ± 17 nm were synthesized by chemical reduction of iron precursors on the surface of montmorillonite (MMT). This active MMT-Fe powder was then uniformly distributed in a linear low-density polyethylene (LLDPE) matrix by extrusion at atmospheric conditions, as confirmed by wide-angle X-ray scattering (WAXS), which also detected a partial exfoliation of the nanoclays. Thermogravimetric analysis (TGA) did not detect any significant modification of the degradation temperature between nanocomposites and active nanocomposites. <sup>57</sup>Fe Mössbauer spectroscopy evidenced the formation of a majority of iron boride in MMT-Fe as well as in the active film containing it. The LLDPE.Fu15.MMT-Fe3.75 and LLDPE.Fu15.MMT-Fe6.25 films had oxygen-scavenging capacities of 0.031 ± 0.002 and 0.055 ± 0.009 g(O<sub>2</sub>)/g(Fe), respectively, while the neat powder had an adsorption capacity of 0.122 g(O<sub>2</sub>)/g(Fe). This result confirms that the fresh film samples were partially oxidized shortly after thermomechanical processing (60% of oxidized species according to Mössbauer spectroscopy). No significant difference in oxygen permeability was observed when MMT-Fe was added. This was related to the relatively small film surface used for measuring the permeability. The reaction-diffusion model proposed here was able to reproduce the observed data of O<sub>2</sub> adsorption in an active nanocomposite, which validated the O<sub>2</sub> adsorption model previously developed for dried MMT-Fe powder. Montmorillonite ; Linear low-density polyethylene ; Thermogravimetric analysis ; Nanocomposite ; Materials science ; Adsorption ; Chemical engineering ; Exfoliation joint ; X-ray photoelectron spectroscopy ; Nuclear chemistry ; Polyethylene ; Composite material ; Organic chemistry ; Chemistry ; Nanotechnology ; Graphene Polymer Nanocomposites and Properties ; Environmental remediation with nanomaterials ; Iron oxide chemistry and applications
Authors: Rajamani Krishna | Jasper M. van Baten
Source: ACS Omega (article, 2019-06-20)
Field: Chemistry — Inorganic Chemistry

Elucidating Traffic Junction Effects in MFI Zeolite Using Kinetic Monte Carlo Simulations Published experimental studies on the diffusion of n-butane (nC4)/iso-butane (iC4), n-hexane (nC6)/2-methylpentane (2MP), and methane/benzene mixtures in MFI zeolite show that the self-diffusivity of the more mobile (linear) alkanes is diminished by about 1–3 orders of magnitude with increasing proportion of the tardier partners (iC4, 2MP, benzene) in the mixture. The strong reduction can be rationalized on the basis of the preferential location of the tardier partners iC4, 2MP, and benzene at the channel intersections of MFI, serving to slow down the molecular traffic. The primary objective of this article is to investigate, and quantify, such traffic junction effects with the aid of kinetic Monte Carlo (KMC) simulations. The KMC simulations show that the preferential location of branched molecules at the channel intersections can be effectively considered as an intersection blocking with attendant loss of connectivity of the MFI topology. Consequently, both the Maxwell–Stefan (M–S) diffusivity and self-diffusivity for nC4 in the nC4/iC4 mixtures are lowered below that for the unary nC4 diffusion by about 2 orders of magnitude. It is also established that such a lowering of the diffusivity of the more mobile partner is distinctly different from the “correlation” effects that generally manifest in the mixture diffusion in microporous materials. Thermal diffusivity ; Kinetic Monte Carlo ; Diffusion ; Chemistry ; Microporous material ; Kinetic energy ; Benzene ; Zeolite ; Butane ; Monte Carlo method ; Chemical physics ; Physical chemistry ; Thermodynamics ; Physics ; Catalysis ; Organic chemistry Zeolite Catalysis and Synthesis ; Advanced NMR Techniques and Applications ; Metal-Organic Frameworks: Synthesis and Applications
Authors: W. Yassine | Souäd Zyade | S. Akazdam | Abdelhafid Essadki | Bouchaib Gourich | Driss Benmessaoud Left
Source: Mediterranean Journal of Chemistry (article, 2019-07-13)
Field: Chemistry — Organic Chemistry

A study of olive mill waste water removal by a biosorbent prepared by olive stones In this work, olive mill wastewater (OMW) such as dyes is very toxic even present as traces in industrial wastewater effluents. It may constitute a potential pollution source of ground waters and hence it has to be eliminated. Various low cost adsorbents have been studied for their applicability in treatment of different types of effluents. In this study, the potential of activated carbon derived from Olive Stones was studied for the removal of OMW. The biosorption of OMW from aqueous solutions by Olive Stones (OLS) as a low-cost, natural and eco-friendly biosorbent was investigated and by KOH and H3PO4 treated Olive Stones (AOLS). Biosorption kinetic data were properly fitted with the pseudo-second-order kinetic model. The experimental isotherm data were analyzed using Langmuir, Freundlich isotherm equations. The best fit was obtained by the Langmuir model with a Langmuir maximum monolayer biosorption capacity of 189,83 mg/g for OMW. The biosorption was exothermic in nature (H° = -105,54 kJ/mol). The reaction was accompanied by a decrease in entropy. The Gibbs energy (G°) increased when the temperature was increased from 303 to 320 °K indicating a decrease in feasibility of biosorption at higher temperatures. The results have established good potentiality for the Olive Stones to be used as a sorbent for the removal of olive mill wastewater. Biosorption ; Chemistry ; Wastewater ; Langmuir adsorption model ; Freundlich equation ; Langmuir ; Effluent ; Sorbent ; Adsorption ; Nuclear chemistry ; Pulp and paper industry ; Aqueous solution ; Environmental engineering ; Organic chemistry ; Environmental science ; Sorption Edible Oils Quality and Analysis ; Adsorption and biosorption for pollutant removal ; Dye analysis and toxicity
Authors: Charles Hall | Aleksandar Ignjatović | Yu Jiang | Patrick A. Burr | Alison Lennon
Source: Journal of Electroanalytical Chemistry (article, 2019-08-18)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Time domain modelling of concurrent insertion and capacitive storage using Laplace domain representations of impedance Capacitance ; Chemistry ; Energy storage ; Capacitor ; Capacitive sensing ; Laplace transform ; Time domain ; Electrical impedance ; Supercapacitor ; Dielectric spectroscopy ; Computer data storage ; Double-layer capacitance ; Analytical Chemistry (journal) ; Voltage ; Electrical engineering ; Electrochemistry ; Thermodynamics ; Electrode ; Physics ; Computer science ; Engineering ; Mathematics ; Mathematical analysis Supercapacitor Materials and Fabrication ; Conducting polymers and applications ; Advancements in Battery Materials
Authors: Chansong Kim | Eunpyo Hong | Chae‐Ho Shin
Source: Catalysts (article, 2019-10-10)
Field: Materials Science — Materials Chemistry

Improvement of Methane Combustion Activity for Pd/ZrO2 Catalyst by Simple Reduction/Reoxidation Treatment The improvement of methane combustion activity was observed in cyclic temperature-programed and isothermal reactions over Pd/ZrO2 catalysts by simple reduction/reoxidation treatment. The catalytic activity increased during the initial stages of isothermal reaction, and the light-off temperature was lowered as the number of cycles increased in the cyclic temperature-programed reaction. To reveal the origin of activation, variations in the reduction properties after the activation period were carefully investigated through CH4 temperature-programed reduction (TPR) measurements. From the CH4-TPR results, it was confirmed that the reduction temperature decreased significantly after activation. The observation of the CH4-TPR peak at relatively low temperatures is directly proportional to the catalytic activity of CH4 combustion. It was therefore concluded that repeated reduction/reoxidation occurred in the reactant stream, and this phenomenon allowed the combustion reaction to proceed more easily at lower temperatures. Catalysis ; Isothermal process ; Methane ; Combustion ; Chemistry ; Catalytic combustion ; Activation energy ; Inorganic chemistry ; Materials science ; Chemical engineering ; Thermodynamics ; Physical chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Industrial Gas Emission Control
Authors: Olha Khemii | I.M. Budzuliak | Volodymyr Kotsyubynsky | L.S. Yablon | R.V. Ilnytskyi | Volodymyra Boychuk | О. V. Morushko | Khrystyna Bandura | Mariia Khemii
Source: Materials Science-Poland (article, 2019-11-29)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Synthesis, morphology, electrical conductivity and electrochemical properties of α-Ni(OH) <sub>2</sub> and its composites with carbon Abstract A simple and effective hydrothermal synthesis of spherical α-Ni(OH) 2 particles and α-Ni(OH) 2 /carbon composites was proposed. The mechanism of ultrafine α-Ni(OH) 2 phase forming and correlations between synthesis conditions, morphology, electrical conductivity were analyzed. It was found that carbon nanoparticles form an electric conductive cover on nickel hydroxide microparticles during synthesis which increases overall electronic conductivity of the composite material. α-Ni(OH) 2 and α-Ni(OH) 2 /C samples were tested as electrodes for hybrid supercapacitors. It was found that carbon coverings stabilize α-Ni(OH) 2 phase in the alkaline medium. The comparison of the influence of laser irradiation and ultrasonic treatment on the electrochemical performance of the obtained materials was made. Materials science ; Electrochemistry ; Supercapacitor ; Morphology (biology) ; Electrical resistivity and conductivity ; Composite number ; Nickel ; Composite material ; Conductivity ; Nanoparticle ; Carbon fibers ; Phase (matter) ; Hydroxide ; Carbon nanotube ; Electrical conductor ; Hydrothermal circulation ; Hydrothermal synthesis ; Electrode ; Chemical engineering ; Nanotechnology ; Metallurgy ; Chemistry ; Organic chemistry Supercapacitor Materials and Fabrication ; Copper-based nanomaterials and applications ; Electrocatalysts for Energy Conversion
Authors: Ekaterina Alekseeva | Аlexander K. Belyaev | A. M. Polyanskiy | Vladimir A. Polyanskiy | Evgeniy Varshavchik | Yuri A. Yakovlev
Source: E3S Web of Conferences (article, 2019-01-01)
Field: Materials Science — Metals and Alloys

Surface vs diffusion in TDS of hydrogen The paper addresses the numerical simulation of conditions in which the measurement of thermal desorption spectra of hydrogen (TDS) is carried out. Plane steel samples of 10 mm thickness were used as the specimens for simulation. The skin effect which is observed with standard hydrogen charging of samples was accounted for the initial conditions. The standard diffusion of hydrogen was simulated according to Fick’s law. Solution of the Fick’s equation is obtained by finite element methods using the developed code. The resulting solutions show that standard hydrogen charging can lead to the appearance of an additional TDS peak, even without taking into account the traps. New interpretation of the TDS method for hydrogen dissolved in a solid was suggested. Hydrogen ; Diffusion ; Thermal desorption ; Materials science ; Desorption ; Analytical Chemistry (journal) ; Plane (geometry) ; Thermodynamics ; Chemistry ; Physical chemistry ; Mathematics ; Adsorption ; Physics ; Chromatography ; Geometry Hydrogen embrittlement and corrosion behaviors in metals ; Material Properties and Failure Mechanisms ; Nuclear Materials and Properties
Authors: Wenyi Wang | Chuan Li | Shun‐Li Shang | Jianzhu Cao | Zi‐Kui Liu | Chao Fang
Source: Journal of Nuclear Materials (article, 2019-07-29)
Field: Materials Science — Materials Chemistry

Study on impact of Cr and Mo on diffusion of H in 2.25Cr1Mo steel using first-principle calculations Diffusion ; Hydrogen ; Activation energy ; Thermodynamics ; Effective diffusion coefficient ; Thermal diffusivity ; Materials science ; Atom (system on chip) ; Work (physics) ; Chemistry ; Physical chemistry ; Atomic physics ; Physics Nuclear Materials and Properties ; Nuclear reactor physics and engineering ; Fusion materials and technologies
Authors: Yan Zhu | Chaoyu Li | Min Chen | Guoxia Zhang | Chengwen Mao | Huamin Kou | Zheng Wang
Source: Atomic Spectroscopy (article, 2019-04-25)
Field: Materials Science — Materials Chemistry

Diffusion Characteristics of Cr Dopant in Cr:ZnS Crystals via Laser Ablation– Inductively Coupled Plasma Mass Spectrometry Analysis Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was applied to characterize the diffusion behavior of doped Cr ions in ZnS crystals, in terms of Cr concentration, diffusion distribution, and diffusion coefficient. For quantification, calibration was performed with matrix-matched specimens prepared by diffusion techniques. The distributions of Cr at the crystal growth crosssections were determined by quantitative mapping to estimate the ion diffusion paths. Spatial variance of the Cr ions was obtained, revealing a sharp doping concentration gradient in the ZnS crystals. Based on the Cr distance-concentration data measured by LA-ICP-MS, the diffusion coefficients for Cr in the ZnS crystals were calculated using Fick's Second Law (simplified). The coefficient values increased with increasing temperature. This study provides not only a practical approach to the measurement of the distribution of a low-level dopant in crystals, but also a computational method for calculating diffusion coefficients from LA-ICP-MS data. Chemistry ; Dopant ; Inductively coupled plasma mass spectrometry ; Analytical Chemistry (journal) ; Diffusion ; Mass spectrometry ; Laser ablation ; Laser ; Doping ; Optoelectronics ; Optics ; Chromatography Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; nanoparticles nucleation surface interactions
Authors: Lesya Коbylinska | Olga Klyuchivska | Roman Lesyk | Rostyslav Stoika
Source: The Ukrainian Biochemical Journal (article, 2019-04-01)
Field: Chemistry — Organic Chemistry

Targeting of the pro-oxidant-antioxidant balance in vitro and in vivo by 4-thiazolidinone-based chemotherapeutics with anticancer potential oxidative stress is one of the main mechanisms by which anticancer chemotherapeutics damage normal tissues and organs. at the same time, it is an important biochemical mechanism of the neoplastic action of such medicines. the aim of the present study was to determine the pro-oxidant-antioxidant balance in vitro and in vivo under the influence of novel 4-thiazolidinone-based chemotherapeutics with anticancer potential. an advantage of using these compounds in vivo is their low general toxicity, compared to doxorubicin (Kobylinska L. et al., 2014(Kobylinska L. et al., , 2015 The 4-thiazolidinone derivatives with previously established anti-neoplastic activity in vitro Doses of the injected drugs equaled 10% of the LD 50 , namely doxorubicin -5.5 mg/kg, 3 mg/kg. the radical scavenging of 1,1-diphenyl-2-picrylhydrazil (DPPH) activity was measured. Concentrations of thio-barbituric acid-active products were assessed in blood serum, liver, heart and kidney tissues of treated rats. additionally, the activities of superoxide dismutase, catalase and glutathione peroxidase were measured in blood serum and these tissues. We found that administration for 20 days of compounds disturbed the pro-oxidant-antioxidant balance in the treated rats. Increased amounts of products of reactions of lipid peroxidation and exhaustion of the enzymatic antioxidant system in liver, heart and kidney tissues were detected. In general, compounds exhibited less pro-oxidant action, compared with the effect of doxorubicin. According to the results of influencing the pro-oxidant-antioxidant balance in the selected tissues, the studied compounds can be ranked in the following order: doxorubicin >> the results of measuring direct scavenging ability of these compounds observed in 24 h suggests their lower toxic effect compared with the effect of the doxorubicin. The obtained results are in correspondence with the results of our recent experiments demonstrating their antineoplastic effect in vitro (Kobylinska L. et al. Chemistry ; Pro-oxidant ; In vivo ; In vitro ; Pharmacology ; Antioxidant ; Biochemistry ; Medicine ; Biology ; Biotechnology Free Radicals and Antioxidants ; Synthesis and biological activity ; Genomics, phytochemicals, and oxidative stress
Authors: Lei Li | Guangming Li
Source: Micromachines (article, 2019-02-20)
Field: Materials Science — Materials Chemistry

High-Performance Resistance-Switchable Multilayers of Graphene Oxide Blended with 1,3,4-Oxadiazole Acceptor Nanocomposite Graphene oxide (GO) has been actively utilized in nonvolatile resistive switching random access memory (ReRAM) devices due to solution-processability, accessibility for highly scalable device fabrication for transistor-based memory, and cross-bar memory arrays. Uncontrollable oxygen functional groups of GO, however, restrict its application. To obtain stable memory performance, 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD) a that can serve as 1,3,4-oxadiazole acceptor was carefully introduced onto the GO framework. Better stability was achieved by increasing the weight ratio of the chemical component from 2:1 to 10:1 in all GO-based solutions. Particularly, rewritable nonvolatile memory characteristics were dependent on the ratio between PBD and GO. PBD:GO devices with a proportion of 10:1 w/w exhibited better memory performance, possessed a higher ON/OFF ratio (>10²) at a lower switching voltage of -0.67 V, and had a long retention ability. The interaction between PBD and GO can be demonstrated by transmission electron microscope, scanning electron microscope, thermogravimetric analysis, fourier transform infrared spectra, Raman spectra, X-ray diffraction, and fluorescence spectra. The superior ReRAM properties of the multilayers of GO blended with the PBD nanocomposite are attributed to electron traps caused by the strong electron acceptors. Graphene ; Nanocomposite ; Materials science ; Oxadiazole ; Oxide ; Acceptor ; Nanotechnology ; Chemistry ; Organic chemistry Graphene research and applications ; Conducting polymers and applications ; Advanced Memory and Neural Computing