jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Faiq F. Karam | Noor Saeed | Ahmed Al‐Yasari | Luma Majeed Ahmed | Hind Saleh
Source: Egyptian Journal of Chemistry (article, 2020-04-04)
Field: Chemistry — Analytical Chemistry

Kinetic Study for Reduced the Toxicity of Textile Dyes (Reactive yellow 14 dye and Reactive green dye) Using UV-A light/ZnO System Several parameters have been studied in this manuscript to investigate the effect of certain conditions on the removal and the decolorization of the textile dyes: reactive yellow 14 (RY 14) and reactive green (RG) dyes from aqueous solution. Parameters such as temperature, initial concentration of dye and initial pH were taken into consideration to reach the perfect removal and decolorization for both dyes. This work was achieved in both dark and photoreaction processes. In dark reaction, the type of adsorption was determined based on Gibb’s free energy values, activation energies and change in enthalpies, which were found that the physical adsorption for removal of both dyes is predominated, and the reaction is exothermic . The adsorption capacity and percentage of removal both dyes elevated with raised the dye concentration. The best initial pH for removal of RY 14 and RG dyes dyes was conducted and found equal to 5.14 and 9.75 respectively. The raised in temperature is not enhanced the adsorption process, that due to the dark reaction for both dye is exothermic. The small negative values of change in entropies are proved the associative mechanism of both dyes on ZnO surface. On the other hand, the results under the percent UV-light showed, that the optimal conditions were found at 303.15 K, with 25 ppm and optimum pH=11.01 for reactive green(RG) dye, while the optimum conditions were appearing at 50 ppm and best pH= 6.075 for reactive yellow 14 at same temperature. The decolorization process for both studied dyes was found to be a pseudo-first-order kinetic, fast (low activation energies), endothermic reaction (positive change in enthalpies), non- spontaneous (positive change Gibbs free energies) and less random (negative change in entropies). The photoreaction is a completed to removal process to depress the toxicity for these studied textiles dyes. Adsorption ; Exothermic reaction ; Chemistry ; Reactive dye ; Aqueous solution ; Activation energy ; Photochemistry ; Acid dye ; Dyeing ; Nuclear chemistry ; Organic chemistry Dye analysis and toxicity ; Dyeing and Modifying Textile Fibers ; Pigment Synthesis and Properties
Authors: E. E. Doğan
Source: Advances in Materials Science (article, 2020-06-01)
Field: Materials Science — Materials Chemistry

Hydrogen Production and Its Storage from Solar Energy Abstract The aim of this study is to increase the energy efficiency of the solar panel, to make the waste heat generated under the panel efficient and to store the electrical energy produced from solar panels in the form of hydrogen in boron nitride and boron carbide. Characterization of boron nitride and boron carbide was carried out with Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), differential thermal and thermogravimetric analysis (DTA/TG), Brunauer–Emmett–Teller (BET) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM/EDX). The specific surface areas and pore sizes of the boron nitride and boron carbide were determined as 78 and 20 m 2 /g; and 3.8 and 11.1 nm, respectively. DTA/TG thermograms showed that boron nitride degraded in one step in the temperature range of 30-550°C and boron carbide degraded in two steps. From experimental studies, approximately 8.7% energy efficiency was achieved and hydrogen energy was costless produced from a renewable energy source excluding system costs. Moreover, it was found that 276% and 208% more hydrogen could be stored in the boron compounds, the boron nitride had more hydrogen storage capacity, and the electrical efficiency of the panel was increased. Materials science ; Boron nitride ; Boron carbide ; Hydrogen storage ; Boron ; Fourier transform infrared spectroscopy ; Hydrogen ; Thermogravimetric analysis ; Nitride ; Carbide ; Hydrogen production ; Chemical engineering ; Analytical Chemistry (journal) ; Metallurgy ; Composite material ; Chemistry ; Organic chemistry Hydrogen Storage and Materials ; Hybrid Renewable Energy Systems ; Ammonia Synthesis and Nitrogen Reduction
Authors: Bożena Łosiewicz | Joanna Maszybrocka | Julian Kubisztal | Grzegorz Skrabalak | Andrzej Stwora
Source: Materials (article, 2020-12-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Corrosion Resistance of the CpTi G2 Cellular Lattice with TPMS Architecture for Gas Diffusion Electrodes The corrosion of materials used in the design of metal-air batteries may shorten their cycle life. Therefore, metal-based materials with enhanced electrochemical stability have attracted much attention. The purpose of this work was to determine the corrosion resistance of commercially pure titanium Grade 2 (CpTi G2) cellular lattice with the triply periodic minimal surfaces (TPMS) architecture of G80, D80, I-2Y80 in 0.1 M KOH solution saturated with oxygen at 25 °C. To produce CpTi G2 cellular lattices, selective laser melting technology was used which allowed us to obtain 3D cellular lattice structures with a controlled total porosity of 80%. For comparison, the bulk electrode was also investigated. SEM examination and statistical analysis of the surface topography maps of the CpTi G2 cellular lattices with the TPMS architecture revealed much more complex surface morphology compared to the bulk CpTi SLM. Corrosion resistance tests of the obtained materials were conducted using open circuit potential method, Tafel curves, anodic polarization curves, and electrochemical impedance spectroscopy. The highest corrosion resistance and the lowest material consumption per year were revealed for the CpTi G2 cellular lattice with TPMS architecture of G80, which can be proposed as promising material with increased corrosion resistance for gas diffusion in alkaline metal-air batteries. Corrosion ; Materials science ; Dielectric spectroscopy ; Tafel equation ; Metallurgy ; Electrochemistry ; Chemical engineering ; Titanium ; Lattice constant ; Metal ; Electrode ; Composite material ; Chemistry Supercapacitor Materials and Fabrication ; Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion
Authors: Fatemeh Mehrali | Hakimeh Ziyadi | Malak Hekmati | Reza Faridi‐Majidi | Mahnaz Qomi
Source: SN Applied Sciences (article, 2020-04-13)
Field: Materials Science — Biomaterials

Kefiran/poly(vinyl alcohol)/poly(vinyl pyrrolidone) composite nanofibers: fabrication, characterization and consideration of effective parameters in electrospinning Vinyl alcohol ; Nanofiber ; Polyvinyl alcohol ; Materials science ; Electrospinning ; Differential scanning calorimetry ; Polymer ; Scanning electron microscope ; Chemical engineering ; Thermogravimetric analysis ; Composite material ; Polymer chemistry Electrospun Nanofibers in Biomedical Applications ; Advanced Sensor and Energy Harvesting Materials ; Conducting polymers and applications
Authors: Jun Shen | Christian Heß
Source: Catalysts (article, 2020-11-28)
Field: Materials Science — Materials Chemistry

High Surface Area VOx/TiO2/SBA-15 Model Catalysts for Ammonia SCR Prepared by Atomic Layer Deposition The mode of operation of titania-supported vanadia (VOx) catalysts for NOx abatement using ammonia selective catalytic reduction (NH3-SCR) is still vigorously debated. We introduce a new high surface area VOx/TiO2/SBA-15 model catalyst system based on mesoporous silica SBA-15 making use of atomic layer deposition (ALD) for controlled synthesis of titania and vanadia multilayers. The bulk and surface structure is characterized by X-ray diffraction (XRD), UV-vis and Raman spectroscopy, as well as X-ray photoelectron spectroscopy (XPS), revealing the presence of dispersed surface VOx species on amorphous TiO2 domains on SBA-15, forming hybrid Si–O–V and Ti–O–V linkages. Temperature-dependent analysis of the ammonia SCR catalytic activity reveals NOx conversion levels of up to ~60%. In situ and operando diffuse reflection IR Fourier transform (DRIFT) spectroscopy shows N–Hstretching modes, representing adsorbed ammonia and -NH2 and -NH intermediate structures on Bronsted and Lewis acid sites. Partial Lewis acid sites with adjacent redox sites are proposed as the active sites and desorption of product molecules as the rate-determining step at low temperature. The high NOx conversion is attributed to the presence of highly dispersed VOx species and the moderate acidity of VOx supported on TiO2/SBA-15. Catalysis ; NOx ; X-ray photoelectron spectroscopy ; Atomic layer deposition ; Raman spectroscopy ; Selective catalytic reduction ; Ammonia ; Lewis acids and bases ; Mesoporous material ; Inorganic chemistry ; Chemistry ; Chemical engineering ; Materials science ; Layer (electronics) ; Nanotechnology ; Physical chemistry ; Combustion ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Transition Metal Oxide Nanomaterials
Authors: Hajime Sasaki | Bunshi Fugetsu | Ichiro Sakata
Source: Applied System Innovation (article, 2020-09-14)
Field: Materials Science — Materials Chemistry

Emerging Scientific Field Detection Using Citation Networks and Topic Models—A Case Study of the Nanocarbon Field In fields with high science linkage, such as the nanocarbon field, trends in academic papers are particularly important for identifying future technological trends. The use of the number of citations allows us to predict the qualitative trends on a paper-by-paper basis. At the same time, it is necessary to be able to comprehensively discuss both qualitative and quantitative aspects in the subject area. This study aimed to detect emerging areas in the nanocarbon field using network models and topic models. It was possible to not only construct a model that exceeded an 86.2% F1 measure but also to focus on an area that could not be detected by the prediction model. This was accomplished by focusing on paper units, such as the research on the chemical synthesis of zigzag single-walled carbon nanotubes. Thus, it is possible to obtain knowledge that contributes to diversified R&amp;D strategies and innovation policies by considering the emergence of new fields from multiple perspectives. Field (mathematics) ; Linkage (software) ; Construct (python library) ; Citation ; Data science ; Scientific field ; Computer science ; Zigzag ; Measure (data warehouse) ; Nanotechnology ; Management science ; Data mining ; Engineering ; Geography ; Mathematics ; Materials science ; Chemistry ; Library science Machine Learning in Materials Science ; scientometrics and bibliometrics research ; Computational Drug Discovery Methods
Authors: Jeffrey Ting | Alexander E. Marras | Joseph D. Mitchell | Trinity Campagna | Matthew Tirrell
Source: Molecules (article, 2020-05-30)
Field: Materials Science — Surfaces, Coatings and Films

Comparing Zwitterionic and PEG Exteriors of Polyelectrolyte Complex Micelles A series of model polyelectrolyte complex micelles (PCMs) was prepared to investigate the consequences of neutral and zwitterionic chemistries and distinct charged cores on the size and stability of nanocarriers. Using aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization, we synthesized a well-defined diblock polyelectrolyte system, poly(2-methacryloyloxyethyl phosphorylcholine methacrylate)-block-poly((vinylbenzyl) trimethylammonium) (PMPC-PVBTMA), at various neutral and charged block lengths to compare directly against PCM structure-property relationships centered on poly(ethylene glycol)-block-poly((vinylbenzyl) trimethylammonium) (PEG-PVBTMA) and poly(ethylene glycol)-block-poly(l-lysine) (PEG-PLK). After complexation with a common polyanion, poly(sodium acrylate), the resulting PCMs were characterized by dynamic light scattering (DLS) and small angle X-ray scattering (SAXS). We observed uniform assemblies of spherical micelles with a diameter ~1.5-2× larger when PMPC-PVBTMA was used compared to PEG-PLK and PEG-PVBTMA via SAXS and DLS. In addition, PEG-PLK PCMs proved most resistant to dissolution by both monovalent and divalent salt, followed by PEG-PVBTMA then PMPC-PVBTMA. All micelle systems were serum stable in 100% fetal bovine serum over the course of 8 h by time-resolved DLS, demonstrating minimal interactions with serum proteins and potential as in vivo drug delivery vehicles. This thorough study of the synthesis, assembly, and characterization of zwitterionic polymers in PCMs advances the design space for charge-driven micelle assemblies. Micelle ; Dynamic light scattering ; Polyelectrolyte ; Ethylene glycol ; Polymer chemistry ; Materials science ; PEG ratio ; Small-angle X-ray scattering ; Copolymer ; Raft ; Chain transfer ; Polymerization ; Chemical engineering ; Polymer ; Aqueous solution ; Chemistry ; Nanoparticle ; Radical polymerization ; Organic chemistry ; Scattering ; Nanotechnology Polymer Surface Interaction Studies ; Surfactants and Colloidal Systems ; Electrostatics and Colloid Interactions
Authors: Han Zhou | Wentian Jin | Sheldon X.-D. Tan
Source:  (article, 2020-11-02)
Field: Materials Science — Electronic, Optical and Magnetic Materials

GridNet Electromigration (EM) is a major failure effect for on-chip power grid networks of deep submicron VLSI circuits. EM degradation of metal grid lines can lead to excessive voltage drops (IR drops) before the target lifetime. In this paper, we propose a fast data-driven EM-induced IR drop analysis framework for power grid networks, named GridNet, based on the conditional generative adversarial networks (CGAN). It aims to accelerate the incremental full-chip EM-induced IR drop analysis, as well as IR drop violation fixing during the power grid design and optimization. More importantly, GridNet can naturally leverage the differentiable feature of deep neural networks (DNN) to obtain the sensitivity information of node voltage with respect to the wire resistance (or width) with marginal cost. Grid-Net treats continuous time and the given electrical features as input conditions, and the EM-induced time-varying voltage of power grid networks as the conditional outputs, which are represented as data series images. We show that GridNet is able to learn the temporal dynamics of the aging process in continuous time domain. Besides, we can take advantage of the sensitivity information provided by GridNet to perform efficient localized IR drop violation fixing in the late stage design and optimization. Numerical results on 36000 synthesized power grid network samples demonstrate that the new method can lead to 105× speedup over the recently proposed full-chip coupled EM and IR drop analysis tool. We further show that localized IR drop violation fix for the same set of power grid networks can be performed remarkably efficiently using the cheap sensitivity computation from GridNet. Power network design ; Computer science ; Voltage drop ; Grid ; Chip ; Electronic engineering ; Voltage ; Electrical engineering ; Engineering ; Mathematics Copper Interconnects and Reliability ; Semiconductor materials and devices ; Low-power high-performance VLSI design
Authors: Hortense Le Ferrand | Sakineh Chabi | Shweta Agarwala
Source: Advanced Intelligent Systems (article, 2020-01-16)
Field: Materials Science — Materials Chemistry

3D Assembly of Graphene Nanomaterials for Advanced Electronics Since the discovery of electricity and the creation of the first transistors two centuries ago, the field of electronics has evolved rapidly to become omnipresent. Today, electronic devices are challenged by new demands in function and performance: they are expected to be lightweight, highly efficient, flexible, smart, implantable, and so on. To meet these demands, the materials and components in devices need to be carefully selected and assembled together. In this regard, the controlled assembly of 3D graphene structures holds tremendous potential to achieve such levels of multifunctionality and outstanding properties. Advanced processing approaches, such as 3D printing, allow the fabrication of a variety of 3D graphene–based materials that present outstanding properties and a high degree of multifunctionality. Herein, the recent progress in the fabrication of graphene‐based devices for advanced electronics using controlled assembly is reported. The benefits of controlling the microstructure of graphene nanomaterials for enhanced properties and functionalities are highlighted, and the various fabrication methods and their implications on the organization of materials are reviewed, as well as selected electrical devices. The approaches described here are opening up new avenues for the fabrication of health or structural monitoring devices, autonomous machines, and interconnected objects. Nanotechnology ; Graphene ; Fabrication ; Electronics ; Nanomaterials ; Materials science ; 3D printing ; Computer science ; Engineering ; Electrical engineering Graphene research and applications ; Supercapacitor Materials and Fabrication ; Advanced Sensor and Energy Harvesting Materials
Authors: Vinicius Rodrigues Viana | Willian H. Ferreira | Edwin G. Azero | Marcos L. Dias | Cristina T. Andrade
Source: Journal of Materials Science and Chemical Engineering (article, 2020-01-01)
Field: Materials Science — Biomaterials

Optimization of the Electrospinning Conditions by Box-Behnken Design to Prepare Poly(Vinyl Alcohol)/Chitosan Crosslinked Nanofibers Electrospun poly(vinyl alcohol)/chitosan nanofibers had their solution and process parameters optimized using a Box-Behnken design and desirability function. Four factors (applied voltage, flow rate, distance tip-to-plate and amount of chitosan) were varied to produce electrospun mats with a low fiber diameter. An empirical model was developed for each response using response surface methodology (RSM), which revealed that flow rate had no significant influence on the assessed responses. With desirability function, the optimal conditions to produce the nanofibers were applied voltage of 13.1 kV, 30% chitosan concentration and distance tip-to-plate of 10 cm. The fiber diameter and standard deviation were 196.5 ± 28.3 nm, compared to the predicted values of 185.9 ± 26.8 nm. The desirability function allied with Box-Benhken design proved themselves important tools to predict process parameters for the development of nanofibers. The mats were crosslinked with glutaraldehyde for 24 h and 48 h and presented good water stability and enhanced mechanical properties. Box–Behnken design ; Vinyl alcohol ; Nanofiber ; Materials science ; Response surface methodology ; Glutaraldehyde ; Chitosan ; Electrospinning ; Composite material ; Volumetric flow rate ; Fiber ; Chemical engineering ; Polymer ; Chromatography Electrospun Nanofibers in Biomedical Applications ; Advanced Sensor and Energy Harvesting Materials ; Conducting polymers and applications
Authors: Zheng Wang | Xiaoming Shi | Xusheng Yang | Wangqiang He | San‐Qiang Shi | Xingqiao Ma
Source: International Journal of Hydrogen Energy (article, 2020-10-19)
Field: Materials Science — Metals and Alloys

Atomistic simulation of the effect of the dissolution and adsorption of hydrogen atoms on the fracture of α-Fe single crystal under tensile load Hydrogen embrittlement ; Materials science ; Hydrogen ; Slip (aerodynamics) ; Dissolution ; Embrittlement ; Coalescence (physics) ; Cleavage (geology) ; Adsorption ; Ultimate tensile strength ; Fracture (geology) ; Crystallography ; Chemical physics ; Metallurgy ; Composite material ; Chemistry ; Thermodynamics ; Physical chemistry ; Corrosion Hydrogen embrittlement and corrosion behaviors in metals ; Nuclear Materials and Properties ; Fusion materials and technologies
Authors: Dimitrios Kilymis | Albert P. Bartók | Chris J. Pickard | Alexander C. Forse | Céline Merlet
Source: Physical Chemistry Chemical Physics (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Efficient prediction of nucleus independent chemical shifts for polycyclic aromatic hydrocarbons Nuclear Magnetic Resonance (NMR) is one of the most powerful experimental techniques to characterize the structure of molecules and confined liquids. Nevertheless, the complexity of the systems under investigation usually requires complementary computational studies to interpret the NMR results. In this work we focus on polycyclic aromatic hydrocarbons (PAHs), an important class of organic molecules which have been commonly used as simple analogues for the spectroscopic properties of more complex systems, such as porous disordered carbons. We use Density Functional Theory (DFT) to calculate 13C chemical shifts and Nucleus Independent Chemical Shifts (NICS) for 34 PAHs. The results show a clear molecular size dependence of the two quantities, as well as the convergence of the 13C NMR shifts towards the values observed for graphene. We then present two computationally cheap models for the prediction of NICS in simple PAHs. We show that while a simple dipolar model fails to produce accurate values, a perturbative tight-binding approach can be successfully applied for the prediction of NICS in this series of molecules, including some non-planar ones containing 5- and 7-membered rings. This model, one to two orders of magnitude faster than DFT calculations, is very promising and can be further refined in order to study more complex systems. Anthracene ; Chemical shift ; Isotropy ; Computational chemistry ; Chemistry ; Molecule ; Polycyclic aromatic hydrocarbon ; Physical chemistry ; Photochemistry ; Physics ; Environmental chemistry ; Organic chemistry Synthesis and Properties of Aromatic Compounds ; Molecular spectroscopy and chirality ; Advanced NMR Techniques and Applications
Authors: T. Egami | Chae Woo Ryu
Source: Frontiers in Chemistry (article, 2020-09-29)
Field: Materials Science — Materials Chemistry

Why Is the Range of Timescale So Wide in Glass-Forming Liquid? The viscosity and the relaxation time of a glass-forming liquid vary over 15 orders of magnitude before the liquid freezes into a glass. The rate of the change with temperature is characterized by liquid fragility. The mechanism of such a spectacular behavior and the origin of fragility have long been discussed, but it remains unresolved because of the difficulty of carrying out experiments and constructing theories that bridge over a wide timescale from atomic (ps) to bulk (minutes). Through the x-ray diffraction measurement and molecular dynamics simulation for metallic liquids we suggest that large changes in viscosity can be caused by relatively small changes in the structural coherence which characterizes the medium-range order. Here the structural coherence does not imply that of atomic-scale structure, but it relates to the coarse-grained density fluctuations represented by the peaks in the pair-distribution function (PDF) beyond the nearest neighbors. The coherence length is related to fragility and increases with decreasing temperature, and it diverges only at a negative temperature. This analysis is compared with several current theories which predict a phase transition near the glass transition temperature. Fragility ; Glass transition ; Coherence (philosophical gambling strategy) ; Relaxation (psychology) ; Viscosity ; Coherence length ; Chemical physics ; Materials science ; Condensed matter physics ; Diffraction ; Range (aeronautics) ; Thermodynamics ; Atmospheric temperature range ; Chemistry ; Physics ; Optics ; Composite material ; Quantum mechanics Material Dynamics and Properties ; Theoretical and Computational Physics ; Glass properties and applications