jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Subita Bhagat
Source: International Journal of All Research Education & Scientific Methods (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Effect of Reaction Parameters on Propylene Polymerization with Me2Si [Ind]2ZrCl2 / MAO Catalytic System Polyolefins are among the largest group of thermoplastics, often referred to as commodity thermoplastics. Metallocene catalysed olefin polymerization has recently attracted research interest since the catalysts allow the production of tailored macro molecules with properties that can be accurately designed due to their single types of sites. Kinetic model plays an important role in designing polymerization conditions to tailor a polymer’s molecular architecture. Valid kinetic rate constants are required for calculating polymerization rates and polymer properties. Kinetic model propylene polymerization with silica supported (dimethylsilylene)bis(ƞ5 -inden-1-ylidene)zirconium dichloride catalyst and methyl alum oxane (MAO) as co catalyst is proposed. In this study, the mechanistic aspects of Me2Si [Ind]2ZrCl2/MAO catalytic system have been studied and used in building up mathematical models for propylene polymerization.. Developed models are validated with the experimental data available in the literature and kinetic parameters are estimated using differential evolution (DE) approach of optimization. Effects of various parameters like catalyst concentration on molecular weight, pressure on molecular weight and hydride activated complex concentration at different temperatures are studied. Polymerization ; Catalysis ; Chemistry ; Polymer chemistry ; Materials science ; Organic chemistry ; Polymer Organometallic Complex Synthesis and Catalysis ; Carbon dioxide utilization in catalysis ; Catalytic Processes in Materials Science
Authors: Xingfei Wei | Zhi Wang | Zhiting Tian | Tengfei Luo
Source: arXiv (Cornell University) (review, 2020-09-20)
Field: Materials Science — Materials Chemistry

Thermal Transport in Polymers: A Review In this article, we review thermal transport in polymers with different morphologies from aligned fibers to bulk amorphous states. We survey early and recent efforts in engineering polymers with high thermal conductivity by fabricating polymers with large-scale molecular alignments. The experimentally realized extremely high thermal conductivity of polymer nanofibers are highlighted, and understanding of thermal transport physics from molecular simulations are discussed. We then transition to the discussion of bulk amorphous polymers with an emphasize on the physics of thermal transport and its relation with the conformation of molecular chains in polymers. We also discuss the current understanding of how the chemistry of polymers would influence thermal transport in amorphous polymers and some limited, but important chemistry-structural-property relationships. Lastly, challenges, perspectives and outlook of this field are presented. We hope this review will inspire more fundamental and applied research in the polymer thermal transport field to advance scientific understanding and engineering applications. Polymer ; Amorphous solid ; Thermal conductivity ; Materials science ; Glass transition ; Nanotechnology ; Chemical physics ; Chemistry ; Organic chemistry ; Composite material Thermal properties of materials ; Graphene research and applications ; Heat Transfer and Optimization
Authors: 黎明 趙
Source: Hokkaido University Collection of Scholarly and Academic Papers (Hokkaido University) (article, 2020-09-25)
Field: Chemistry — Organic Chemistry

Theoretical Study on the Mechanism of Transition Metal Catalyzed Reactions and Spin-Forbidden Reactions Mechanism (biology) ; Catalysis ; Transition metal ; Chemistry ; Chemical physics ; Physics ; Quantum mechanics Nanomaterials for catalytic reactions ; Theoretical and Computational Physics ; nanoparticles nucleation surface interactions
Authors: Mohammad Anisur Rahman Jamil
Source: Hokkaido University Collection of Scholarly and Academic Papers (Hokkaido University) (article, 2020-03-25)
Field: Chemistry — Inorganic Chemistry

Sustainable Heterogeneous Catalysis for C-C/C-N Coupling using Methanol and Triglyceride Methanol ; Catalysis ; Triglyceride ; Coupling (piping) ; Chemistry ; Materials science ; Biochemistry ; Organic chemistry ; Cholesterol ; Metallurgy Asymmetric Hydrogenation and Catalysis ; Catalytic Cross-Coupling Reactions ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Leila Javazmi | Tobias Low | Anthony Young | Gavin Ash
Source: University of Southern Queensland ePrints (University of Southern Queensland) (article, 2020-02-09)
Field: Materials Science — Biomaterials

Effect of various urea concentrations on nitrogen slow release from PLLA nanofiber mat Urea is a cost-effective fertilizer used to promote plant growth and increase crop production. However, uncontrolled use of urea fertilizer is harmful to plants and can lead to soil and water pollution. This study aimed to investigate the effect of different urea concentrations on nitrogen slow release rate from electrospun Poly (L-lactide) (PLLA) nanofibers. Results showed increasing urea percentage loaded into nanofibers from 10% to 40% led to larger nanofiber diameters and increased initial rate of nitrogen release. Furthermore, nanofiber samples released nitrogen for three months, although high urea concentration did not affect the nitrogen release rate significantly. Urea ; Nanofiber ; Nitrogen ; Coated urea ; Fertilizer ; Chemistry ; Controlled release ; Ammonia volatilization from urea ; Agronomy ; Materials science ; Composite material ; Nanotechnology ; Biochemistry ; Organic chemistry ; Biology Electrospun Nanofibers in Biomedical Applications
Authors: Aditya Nandy | Heather J. Kulik
Source: ChemRxiv (preprint, 2020-10-05)
Field: Chemistry — Inorganic Chemistry

Why Conventional Design Rules for C–H Activation Fail for Open-Shell Transition-Metal Catalysts The design of selective and active C–H activation catalysts for direct methane-to-methanol conversion is challenging. Bioinspired complexes that form high valent metal-oxo intermediates capable of hydrogen abstraction and rebound hydroxylation are promising candidates. This promise has made them a target for computational high-throughput screening, typically simplified through the use of linear free energy relationships (LFERs). However, their mid-row transition-metal centers have numerous accessible spin and oxidation states that increase the combinatorial scale of design efforts. Here, we carry out a computational design screen of over 2,500 mid-row 3d transition-metal complexes with four metals in numerous spin and oxidation states. We demonstrate the importance of spin/oxidation state in dictating design principles, limiting the generalization of strategies derived for widely studied high-spin Fe(II) catalysts to other metals or spin/oxidation states. Combined assessment of the effect of ligand field tuning on reaction step energetics and on the identity of the ground state allows us to propose refined design strategies for spin-allowed methane-to-methanol catalysis. We observed weak coupling of energetics and design principles between reaction steps (e.g., oxo-formation vs methanol release), meaning that LFERs do not generalize across our larger catalyst set. To rationalize relative reactivity in known catalysts, we instead compute independent reaction energies and propose strategies for further improvements in catalyst design. Catalysis ; Transition metal ; Chemistry ; Spin states ; Combinatorial chemistry ; Density functional theory ; Methanol ; Transition state ; Reactivity (psychology) ; Oxidation state ; Rational design ; Computational chemistry ; Chemical physics ; Nanotechnology ; Materials science ; Inorganic chemistry ; Organic chemistry Asymmetric Hydrogenation and Catalysis ; Electrocatalysts for Energy Conversion ; CO2 Reduction Techniques and Catalysts
Authors: Nathaniel Morgan Charest
Source: eScholarship (California Digital Library) (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Computational Model Development and Validation on Systems of Biochemical Polymers Modeling of biochemical polymers using classical simulation and the analysis of large datasets has become important in an age when high-throughput experimentation and advanced computational resources have enabled the collection of massive bodies of information regarding these systems. Models help us understand and extract insight from experimental data, allowing us to develop simulations and predictions around their behavior that can help elucidate macroscopic behaviors of interest. The body of work applies techniques in molecular dynamics, machine intelligence and information theory to problems within the realm of biological heteropolymers with the intent of developing understanding regarding modern methods of data generation and analysis. The differing paradigms of first-principles models versus data first models are considered and examined, and work is done to show areas where the methods are complementary or applicable to helping understand experimental data sets. Computer science ; Data science ; Computational model ; Realm ; Artificial intelligence ; Management science ; Engineering Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Scientific Computing and Data Management
Authors: Kurbangali Tynyshtykbayev | Chistos Spitas | Κωνσταντίνος Κώστας | Z. Insepov
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

GRAPHENE LOW-TEMPERATURE SYNTHESIS ON POROUS SILICON The possibility of low-temperature synthesis of graphene on the surface of porous silicon (PS) is associated with the excess surface energies of nc-PS nanocrystallites ; the boundary interface nanocrystallties nc-PS / c-Si monocrystal matrix; the dangling bonds of silicon atoms of nanocrystallites skeleton nc-PS. This opens up new prospects for the development of methods for the low-temperature synthesis of graphene without metal catalysts for the decomposition of carbon precursors, including using the ALD method. Materials science ; Dangling bond ; Silicon ; Graphene ; Porous silicon ; Chemical engineering ; Carbon fibers ; Catalysis ; Porosity ; Nanotechnology ; Optoelectronics ; Composite material ; Chemistry ; Composite number ; Organic chemistry Graphene research and applications ; Carbon Nanotubes in Composites ; Silicon Nanostructures and Photoluminescence
Authors: А. П. Коханенко | Vladimir V. Dirko | Kiril Lozovoy
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

DEPENDENCE OF ELASTIC STRESSES ON THE THICKNESS OF THE DEPOSITED MATERIAL FOR GERMANIUM GROWTH ON SILICON In this work, the dependences of the elastic stresses on the thickness of the deposited material during the growth of germanium quantum dots on silicon have been determined by the fast electron diffraction method. It is shown that the relative value substrate in this system reaches 12.5%. Germanium ; Silicon ; Materials science ; Substrate (aquarium) ; Diffraction ; Work (physics) ; Silicon-germanium ; Composite material ; Optoelectronics ; Condensed matter physics ; Optics ; Geology ; Thermodynamics ; Physics Silicon Nanostructures and Photoluminescence
Authors: Atif Alkhazali | Akram Alsukker | Morad Etier | Mohammad M. Hamasha
Source: Universal Journal of Mechanical Engineering (article, 2020-05-01)
Field: Chemistry — Inorganic Chemistry

Modeling the Impedance Behavior of Ionic Conductors (AgPO&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;1-x&lt;/sub&gt;(Ag&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;x&lt;/sub&gt; Glass System Using Artificial Neural Network The dielectric permittivity and conductivity of (AgPO<sub>3</sub>)<sub>1-x</sub>(Ag<sub>2</sub>SO<sub>4</sub>)<sub>x</sub> compound was investigated at different concentrations of (Ag<sub>2</sub>SO<sub>4</sub>). The effect of concentration on AC conductivity and permittivity as well as temperature and frequency was investigated in order to model this behavior. Multidimensional mathematical models were as proposed to predict the impedance components <img src=image/15115401_01.gif> and the dielectric permittivity components <img src=image/15115401_02.gif> of the glass system as a function of temperatures, frequencies and concentrations. Artificial Neural Network (ANN) and nonlinear regression approaches were set as curve fitting techniques in order to construct models based on 1700 points of data. This model can be then used to predict these proprieties at any concentration and therefore helping the product designer to choose the proper mixing and temperature conditions. For ANN, 20, 50, and 100 nodes in a single hidden layer neural network were considered. Although data results of the two approaches showed a good alignment with experimental data, the ANN model with twenty nodes was able to predict the outputs with lower MSE values range from 0.008 to 0.012 for impedance and from 0.006 to 0.008 for dielectric losses than the regression technique. Moreover, R<sup>2</sup> values for the neural network were over 99% in both training and testing of impedance and dielectric permittivity while R<sup>2</sup> values for non-linear regression vary between 73.86% to 94.75%. The proposed ANN model can be of a great help to find the optimal dielectric permittivity and conductivity of (AgPO<sub>3</sub>)<sub>1-x</sub>(Ag<sub>2</sub>SO<sub>4</sub>)<sub>x</sub> compound when dealing with a specific application. Electrical impedance ; Electrical conductor ; Artificial neural network ; Materials science ; Electrical engineering ; Engineering ; Computer science ; Composite material ; Artificial intelligence Pigment Synthesis and Properties
Authors: V. A. Antonov | Vladimir Popov | Sergey Tarkov | I. E. Tyschenko
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

STRUCTURAL AND ELECTROPHYSICALLY PERFECT SILICONSAPPHIRE HETEROPAIRS WITH A HIGH-K INTERLAYER DIELECTRIC This work investigates the features of the formation of a silicon-sapphire interlayer heterointerface obtained by direct splicing, both with an intermediate amorphous dielectric (Hf, Zr, Al; AlN oxides) and without it. The results of structural and electrophysical studies of these structures are presented. Dielectric ; Sapphire ; Materials science ; Amorphous solid ; Silicon ; Amorphous silicon ; Optoelectronics ; Work (physics) ; Condensed matter physics ; Electronic engineering ; Engineering physics ; Crystallography ; Crystalline silicon ; Chemistry ; Optics ; Physics ; Thermodynamics ; Engineering Silicon Nanostructures and Photoluminescence ; Photonic Crystals and Applications ; Semiconductor materials and interfaces
Authors: IPP SB RAS | Ida Tyschenko
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

NANOMETER THICKNESS SILICON-ON-INSULATOR FILMS THERMAL STABILITY Thermal stability of 2.2 and 4.7 nm thick silicon-oninsulator films was studied within anneal temperature range of 800-1100оС. It was found that at the higher temperatures film thickness decreases and stoichiometric composition changes with increasing the proportion of the amorphous phase. Mechanisms of structural stability dependence upon film thickness is discussed. Materials science ; Thermal stability ; Silicon ; Nanometre ; Composite material ; Amorphous solid ; Annealing (glass) ; Silicon on insulator ; Thermal ; Atmospheric temperature range ; Insulator (electricity) ; Optoelectronics ; Crystallography ; Chemical engineering ; Thermodynamics ; Chemistry Silicon Nanostructures and Photoluminescence ; Nanowire Synthesis and Applications ; Thin-Film Transistor Technologies
Authors: Andrey Solovev
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

FOREIGN METHODS FOR ASSESSING THE RELIABILITY OF ELECTRONIC COMPONENTS The article discusses foreign standards for determining the parameters of the reliability of microcircuits, a comparative analysis of methods for calculating reliability and their applicability to domestic microcircuits is carried out. Reliability (semiconductor) ; Reliability engineering ; Computer science ; Circuit reliability ; Reliability theory ; Electronic engineering ; Engineering ; Failure rate ; Physics Advanced Materials and Semiconductor Technologies ; Industrial Engineering and Technologies ; Engineering Diagnostics and Reliability
Authors: Sergey Gorokhov
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

INVESTIGATION OF BARRIER LAYERS FOR THE FORMATION OF COPPER VIAS The paper investigates possible barrier layers (Ti/TiN/Ti, Ti/TiN/Ta, TaN/Ta) for forming vias to transistor structures made of copper. Tin ; Copper ; Materials science ; Barrier layer ; Optoelectronics ; Transistor ; Metallurgy ; Layer (electronics) ; Composite material ; Electrical engineering ; Engineering Copper Interconnects and Reliability ; 3D IC and TSV technologies ; Semiconductor materials and interfaces
Authors: S.M. Otazhonov | Nodir Alimov | K.A. Botirov
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

MEMORY DEVICE BASED ON CDTE-SIO2-SI HETEROSTRUCTURE In this paper, an increase in the operational control of long-term information storage based on the CdTe-SiO2-Si heterostructure is considered, and the selectivity of a wide range of radiation in the range of 0.5-3.0 microns is shown. Heterojunction ; Cadmium telluride photovoltaics ; Optoelectronics ; Materials science ; Range (aeronautics) ; Silicon ; Radiation ; Computer science ; Optics ; Composite material ; Physics Phase-change materials and chalcogenides ; Advanced Semiconductor Detectors and Materials ; Semiconductor Quantum Structures and Devices
Authors: A. S. Mazinov | Andrey S. Tyutyunik | В.С. Гурченко
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

SYNTHESIS AND CONDUCTING PROPERTIES OF SILICONCARBON NANOSTRUCTURES OBTAINED BY THE METHOD HIGH-TEMPERATURE PLASMA-CHEMICAL SYNTHESIS A method for obtaining nanostructured carbon and silicon powder materials is considered. Shown are micrographs of the obtained nanocrystalline silicon. The temperature dependences of the conductivity of nanocrystalline silicon, fullerene-containing material, and a silicon-carbon compound obtained by plasma-chemical synthesis are presented. Silicon ; Nanocrystalline material ; Materials science ; Nanocrystalline silicon ; Carbon fibers ; Plasma ; Nanostructure ; Chemical engineering ; Conductivity ; Electrical resistivity and conductivity ; Fullerene ; Nanotechnology ; Crystalline silicon ; Composite material ; Optoelectronics ; Chemistry ; Organic chemistry ; Physical chemistry ; Composite number Carbon Nanotubes in Composites ; Diamond and Carbon-based Materials Research ; Laser-Ablation Synthesis of Nanoparticles
Authors: V. A. Terekhov | E. I. Terukov | Yurii K. Undalov | Konstantin A. Barkov | П. В. Середин | D. L. Goloshchapov | Igor E. Zanin | É. P. Domashevskaya
Source: International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis (article, 2020-09-09)
Field: Materials Science — Materials Chemistry

THE NANOCRYSTALS SIZE ESTIMATION USING RAMAN SPECTROSCOPY IN A-SIOX:H FILMS AFTER CRYSTALLIZATION OF SILICON NANOCLUSTERS The a-SiOx thin films with silicon nanoclusters are currently being actively studied by various laboratories due to the possibility of efficient control of their optical properties, both at the stage of formation and using technological treatments. The presence of excess silicon in such films leads to the growth of nanocrystals during high-temperature annealing, which affects the optical properties of SiOx films, including photoluminescence. Therefore, in this work, we studied the formation of silicon nanocrystals in a-SiOx films during Pulse Photon Annealing (PPA). X-ray diffraction studies of SiOx films with different silicon contents have shown that, upon PPA annealing, arrays of silicon nanocrystals of significantly different average sizes are formed. Moreover, according to the Raman spectroscopy data, PPA does not lead to complete ordering of the structural network of silicon atoms, and some of the atoms, apparently located in small clusters of ~1 nm, retain deviations from interatomic distances and bond angles. Nanoclusters ; Silicon ; Materials science ; Raman spectroscopy ; Photoluminescence ; Annealing (glass) ; Nanocrystal ; Nanocrystalline silicon ; Crystallization ; Spectroscopy ; Nanotechnology ; Analytical Chemistry (journal) ; Optoelectronics ; Crystalline silicon ; Amorphous silicon ; Chemical engineering ; Optics ; Chemistry ; Composite material Silicon Nanostructures and Photoluminescence ; Thin-Film Transistor Technologies ; Quantum Dots Synthesis And Properties