jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: V. F. Onyshchenko | Л. А. Карачевцева
Source: Semiconductor Physics Quantum Electronics & Optoelectronics (article, 2020-03-23)
Field: Materials Science — Materials Chemistry

Effective minority carrier lifetime in double-sided macroporous silicon In this paper, we showed that the effective lifetime of minority charge carriers in double-sided macroporous silicon is determined from a system of two transcendental equations.This system of equations is transformed into a system of equations for determining the effective lifetime of minority charge carriers for monocrystalline silicon in the absence of macropores.The system of equations was found by solving the diffusion equation for minority carriers, recorded for two macroporous layers and a monocrystalline substrate between them.The solution of the nonstationary diffusion equation written for two layers of macroporous silicon and a monocrystalline substrate between them are complemented with boundary conditions on the surfaces of the sample of macroporous silicon and on the boundary between each macroporous layer and monocrystalline substrate.The effective lifetime of minority carriers in the double-sided macroporous silicon depends on such values as: the bulk lifetime of minority carriers, diffusion coefficient of minority carriers, and thickness of the monocrystalline substrate between macroporous layers.In addition, the effective lifetime depends on the values inherent to each macroporous layer: the depth of the macropores, average diameter of macropores, average distance between the centers of macropores, volume fraction of macropores, rate of surface recombination.Effective recombination of excess charge carriers in the doublesided macroporous silicon is defined by recombination of excess charge carriers on the surface of macropores and limited by diffusion of charge carriers from the monocrystalline substrate to recombination surfaces in each macroporous layer.We calculated the effective lifetime of minority carriers in the double-sided macroporous silicon depending on the depth of macropores.We used a numerical method to verify the accuracy of calculations performed using the system of analytical equations, which defines the effective lifetime of minority charge carriers in the double-sided macroporous silicon.The numerical method showed the coincidence of calculations aimed at the effective lifetime of minority carriers.We observed a discrepancy of calculations, when the sum of the depths of macropores in two macroporous layers is close to the thickness of macroporous silicon sample. Silicon ; Carrier lifetime ; Materials science ; Optoelectronics Silicon Nanostructures and Photoluminescence ; Semiconductor materials and devices ; Nanowire Synthesis and Applications
Authors: Shraddha Phadke | Rakesh R. Somani | Devender Pathak
Source: Journal of Applied Pharmaceutical Science (article, 2020-09-04)
Field: Chemistry — Organic Chemistry

New benzimidazole derivatives as inhibitors of Pteridine reductase 1: Design, molecular docking study and ADMET prediction Pteridine reductase 1 (PTR1) is a unique enzyme required for survival of Leishmania species, a causative organism for the disease leishmaniasis. We herein report the design, docking, and Absorption, Distribution, Metabolism, Excretion, Toxicity (ADMET) prediction studies of 2-substituted-5-[(6-substituted-1H-benzimidazol-2yl)methyl]azole derivatives (B1-B14) as PTR1 inhibitors. Molecular docking studies showed good binding interaction of the compounds with the active site of pteridine reductase from Leishmania Major, with compounds B5 and B12 showing docking scores of -61.5232 and -62.5897, respectively, which were comparable with the original ligand, dihydrobiopterin. Large substituents on the azole ring, as well as substitutions on sixth position of the benzimidazole ring, were found to be favorable for interaction with PTR1 active site. Physicochemical properties, bioactivity prediction, and toxicity profiles of the compounds were studied using the Molinspiration and admetSAR web servers. All compounds followed Lipinski's rule of five and can be considered as good oral candidates. Bioactivity prediction indicated that the compounds were enzyme inhibitor, thus the rationale for designing PTR1 inhibitors was met. Most of the compounds were predicted to have good ADMET properties in terms of Gastrointestinal (GI) absorption, absence of P-glycoprotein interaction, and LD 50 values in rats. The designed molecules can be further explored for their antileishmanial activity. Benzimidazole ; In silico ; Docking (animal) ; Chemistry ; Pteridine ; Nitric oxide ; Combinatorial chemistry ; Computational biology ; Stereochemistry ; Biochemistry ; Enzyme ; Biology ; Medicine ; Organic chemistry Synthesis and biological activity ; Cancer therapeutics and mechanisms ; Enzyme function and inhibition
Authors: Wenjie Yu | Hengye Li | Lin Zhang | Jing Liu | Fen‐Ying Kong | Wei Wang
Source: SN Applied Sciences (article, 2020-03-09)
Field: Materials Science — Materials Chemistry

Cationic porous aromatic framework with hierarchical structure for selective, rapid and efficient removal of anionic dyes from water Adsorption ; Cationic polymerization ; Microporous material ; Chemical engineering ; Porosity ; Desorption ; Materials science ; Chemistry ; Organic chemistry ; Polymer chemistry Covalent Organic Framework Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Membrane Separation and Gas Transport
Authors: Perumal Prabhakaran | Perumal Rajakumar
Source: RSC Advances (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Regio- and stereoselective synthesis of spiropyrrolidine-oxindole and bis-spiropyrrolizidine-oxindole grafted macrocycles through [3 + 2] cycloaddition of azomethine ylides A convenient and efficient method for the regioselective macrocyclization of triazole bridged spiropyrrolidine-oxindole, and bis-spiropyrrolizidine-oxindole derivatives was accomplished through intra and self-intermolecular [3 + 2] cycloaddition of azomethine ylides. The chalcone isatin precursors 9a-i required for the click reaction were obtained from the reaction of <i>N</i>-alkylazidoisatin 4 and propargyloxy chalcone 8a-i which in turn were obtained by the aldol condensation of propargyloxy salicylaldehyde 6 and substituted methyl ketones 7a-i. The regio- and stereochemical outcome of the cycloadducts were assigned based on 2D NMR and confirmed by single crystal XRD analysis. High efficiency, mild reaction conditions, high regio- and stereoselectivity, atom economy and operational simplicity are the exemplary advantages of the employed macrocyclization procedure. Oxindole ; Chemistry ; Isatin ; Cycloaddition ; Stereoselectivity ; Regioselectivity ; Salicylaldehyde ; Chalcone ; Aldol condensation ; Stereochemistry ; Combinatorial chemistry ; Catalysis ; Organic chemistry ; Schiff base Click Chemistry and Applications ; Carbohydrate Chemistry and Synthesis ; Chemical Synthesis and Analysis
Authors: Alexandrina Nan | Rodica Turcu
Source: Revue Roumaine de Chimie (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Poly(1-vinylimidazole) grafted on magnetic nanoparticles - attainment of novel nanostructures New magnetic core shell nanoparticles were synthesized consisting of a magnetite core and a poly (1-vinylimidazole) shell. Magnetite nanoparticles were first coated by bis(methacryloyloxyethoxy)phosphate as a reactive alkene-containing anchor followed by radical polymerization of 1-vinylimidazole. The poly(1vinylimidazole) coated magnetic nanoparticles (MNP-PVIm) represent versatile magnetic nanoplatforms capable of complexing different types of metals. Their chemical structure was investigated by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The novel nanostructures MNP-PVIm were used as a promising platform for complexing rare earth metals, as gadolinium, terbium, erbium and europium. The morphology and the content of rare earth metals were determined by Transmission Electron Microscopy Energy-Dispersive X-ray spectroscopy (TEM-EDX). The magnetization curves of MNP-PVIm demonstrate the superparamagnetic nature of these nanostructures. X-ray photoelectron spectroscopy ; Superparamagnetism ; Fourier transform infrared spectroscopy ; Materials science ; Nanoparticle ; Magnetite ; Polymerization ; Nanostructure ; Chemical engineering ; Magnetic nanoparticles ; Gadolinium ; Europium ; Transmission electron microscopy ; Nanotechnology ; Nuclear chemistry ; Magnetization ; Chemistry ; Polymer ; Luminescence Electromagnetic wave absorption materials ; Polymer Nanocomposites and Properties ; biodegradable polymer synthesis and properties
Authors: Yaoguang Zhai | Alessandro Caruso | Sicun Gao | Francesco Paesani
Source: ChemRxiv (preprint, 2020-01-22)
Field: Materials Science — Materials Chemistry

Active Learning of Many-Body Configuration Space: Application to the Cs+–water MB-nrg Potential Energy Function as a Case Study The efficient selection of representative configurations that are used in high-level electronic structure calculations needed for the development of many-body molecular models poses a challenge to current data-driven approaches to molecular simulations. Here, we introduce an active learning (AL) framework for generating training sets corresponding to individual many-body contributions to the energy of a N-body system, which are required for the development of MB-nrg potential energy functions (PEFs). Our AL framework is based on uncertainty and error estimation, and uses Gaussian process regression (GPR) to identify the most relevant configurations that are needed for an accurate representation of the energy landscape of the molecular system under exam. Taking the Cs+–water system as a case study, we demonstrate that the application of our AL framework results in significantly smaller training sets than previously used in the development of the original MB-nrg PEF, without loss of accuracy. Considering the computational cost associated with high-level electronic structure calculations for training set configurations, our AL framework is particularly well-suited to the development of many-body PEFs, with chemical and spectroscopic accuracy, for molecular simulations from the gas to condensed phase. Computer science ; Representation (politics) ; Process (computing) ; Potential energy ; Function (biology) ; Energy (signal processing) ; Statistical physics ; Physics ; Mathematics ; Atomic physics ; Statistics Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Protein Structure and Dynamics
Authors: Pian Liu | Yao Shan | Yao Chen | Haotian Zhang | Caiqin Han | Changchun Yan | Yu-Xiang Zheng | Rongjun Zhang | Songyou Wang | Jing Li | Liang‐Yao Chen
Source: The Journal of Physical Chemistry C (article, 2020-12-14)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Characterization on Percolation of Nanostructured Silver Films by the Topological Properties of Spectroscopic Ellipsometric Parameter Trajectories Silver (Ag) films with different nanostructures were prepared by electron beam evaporation and characterized by spectroscopic ellipsometry in combination with X-ray diffraction and field emission scanning electron microscopy (FESEM). The percolation threshold and the nanostructures of Ag films can be deduced from the measured ellipsometric parameters (Ψ, Δ). According to the different topological properties of (Ψ, Δ) trajectories, the percolation threshold of Ag films was determined to lie between the coverage of 66 and 79.6%. The result was further confirmed by the plus–minus sign of the real part of the dielectric function in the infrared. Silver particles, coalescence, networks, and continuous nanostructures were clearly identified from the topological properties of the tangent azimuth of (Ψ, Δ) trajectories, which were verified by the FESEM results. This work is useful for monitoring the fabrication of nanostructure materials in the industry and research field. In addition, it has potential applications on the recognition of micro–nanostructures in the artificial intelligence field. Nanostructure ; Materials science ; Percolation threshold ; Dielectric ; Percolation (cognitive psychology) ; Characterization (materials science) ; Coalescence (physics) ; Field emission microscopy ; Nanotechnology ; Diffraction ; Topology (electrical circuits) ; Optics ; Optoelectronics ; Physics ; Electrical resistivity and conductivity ; Mathematics Gold and Silver Nanoparticles Synthesis and Applications ; Theoretical and Computational Physics ; Nanocluster Synthesis and Applications
Authors: Abed Al Aziz Al Quntar | H. Dweik | Ahmad Al‐Jabareen | Tatyana A. Gloriozova | Valery M. Dembitsky
Source: International Journal of Organic Chemistry (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

An Aminopyrrolidinyl Phosphonates—A New Class of Antibiotics: Facile Synthesis and Predicted Biological Activity A novel class of aminopyrrolidinyl phosphonates was synthesized in 74% - 80% isolated yield by the addition of three-fold excess of primary amines to diethyl 4-chloro-1-butynylphosphonates. The reaction was carried out at room temperature and in the absence of solvent or catalyst to give solely compounds which showed predicted biological activity based on PASS program. Some of the synthesized derivatives of antibiotics exhibit properties for the treatment of stroke, the treatment of acute neurological disorders, and can also be acetyl esterase inhibitors. Class (philosophy) ; Antibiotics ; Biological activity ; Chemistry ; Computer science ; Biology ; Microbiology ; Artificial intelligence ; Biochemistry Organophosphorus compounds synthesis ; Click Chemistry and Applications ; Synthesis and Reactivity of Sulfur-Containing Compounds
Authors: Anne-Laure Moriaux | R. Vallon | Clara Cilindre | Frédéric Polak | B. Parvitte | Gérard Liger‐Belair | V. Zéninari
Source: Infrared Physics & Technology (article, 2020-07-15)
Field: Chemistry — Spectroscopy

A first step towards the mapping of gas-phase CO2 in the headspace of champagne glasses Galvanometer ; Materials science ; Homogeneity (statistics) ; Gas phase ; Phase (matter) ; Laboratory flask ; Optics ; Analytical Chemistry (journal) ; Laser ; Chemistry ; Chromatography ; Computer science ; Physics ; Thermodynamics Spectroscopy and Laser Applications ; Advanced Chemical Sensor Technologies ; Fermentation and Sensory Analysis
Authors: Haibao Lu | Xiaodong Wang | Mokarram Hossain | Yongqing Fu
Source: Macromolecular Chemistry and Physics (article, 2020-06-11)
Field: Materials Science — Polymers and Plastics

A Methodology of Hydrodynamic Complexity in Topologically Hyper‐Branched Polymers Undergoing Hierarchical Multiple Relaxations Abstract A hydrodynamic model is proposed to describe conformational relaxation of molecules, viscoelasticity of arms, and hierarchical multiple‐shape memory effect (multi‐SME) of hyper‐branched polymer. Fox–Flory and Boltzmann’s principles are employed to characterize and predict the hierarchical relaxations and their multi‐SMEs in hyper‐branched polymers. A constitutive relationship among relaxation time, molecular weight, glass transition temperature, and viscoelastic modulus is then formulated. Results reveal that molecular weight and number of arms of the topologically hyper‐branched polymers significantly influence their hydrodynamic relaxations and shape memory behaviors. The effectiveness of model is demonstrated by applying it to predict mechanical and shape recovery behaviors of hyper‐branched polymers, and the theoretical results show good agreements with the experimental ones. This study is expected to provide an effective guidance on designing multi‐SME in topologically hyper‐branched polymers. Viscoelasticity ; Polymer ; Glass transition ; Shape-memory polymer ; Relaxation (psychology) ; Materials science ; Dynamic mechanical analysis ; Polymer chemistry ; Modulus ; Polymer science ; Thermodynamics ; Statistical physics ; Composite material ; Physics Polymer composites and self-healing ; Polymer Nanocomposites and Properties ; Dielectric materials and actuators
Authors: Ineta Vilumsone-Nemes | Dana Beļakova
Source: Industria Textila (article, 2020-06-28)
Field: Materials Science — Polymers and Plastics

Reduction of material consumption for garments from checked fabrics The use of CAD/CAM systems have greatly optimized material utilization of garment styles from plain fabrics. Processing of intricate pattern materials is still work and material consuming. Increased material consumption is obtained because of two reasons: necessity to match pattern on ready garments and unfixed textile material structure. The fabric loss related to the pattern matching necessity is the most difficult to reduce. A style of classical women jacket was tested to compare efficiency of plain and checked fabric markers for sizes 36 – 54. It was determined that marker length is dependent on the conformity of the size of the checked fabric repeat and the length of the longest components placed in a sectioned marker. Reducing the length of the style slightly it was possible to reduce marker length considerably for certain size markers. Marker length, fabric consumption and, with it, product costs can be reduced conforming the length of the style to the size of the checked fabric repeat. Length tolerance – acceptable slight variations of the length of the style which does not change design and visual perception of the style should be determined by designers. Specialized software could be developed to vary the length of the style in the interval of length tolerance to reduce fabric consumption and with it product costs of certain production orders. Improving manufacturing efficiency and reducing fabric use, the styles from checked materials could be included in garment collections more often. Clothing ; Engineering drawing ; Reduction (mathematics) ; Computer science ; Consumption (sociology) ; Textile ; Process engineering ; Materials science ; Mathematics ; Engineering ; Composite material ; Geometry ; Aesthetics ; Art Textile materials and evaluations ; Additive Manufacturing and 3D Printing Technologies ; 3D Shape Modeling and Analysis
Authors: Yetanawork Teyeme | Benny Malengier | Tamrat Tesfaye | Simona Vasile | Lieva Van Langenhove
Source: Tekstilec (article, 2020-11-20)
Field: Materials Science — Polymers and Plastics

Comfort Evaluation of Cyclists Jerseys Using Wear Trial Test The aim of this study was to evaluate the wear comfort of four commercially available cycling outfits and under¬stand various subjective parameters of garments through consumer perception, which will enable the design and development of an optimized outfit. A questionnaire was developed specifically to address various key aspects such as tactile sensation, garment fit with reference to size, garment assembly, garment aesthetics (style and shape), comfort (before, during and after wearing) and overall satisfaction (relating to design of the garment and style). Three outfits were fabricated from polyester fabric and one from polyamide/elastane (80%/20%) fabric. They were assessed by four male professional cyclists (age 22−25) at various stages of a test protocol of 45 minutes total duration, of which 20 minutes was flat cycling. The four tested garments showed greater dif¬ferences between the sensorial comfort perceptions than thermophysiological comfort. The sensorial comfort sensation was found to be mainly correlated with fabric properties, fit, construction techniques and moisture sensation, whereas the thermophysiological comfort was found to be affected by the fabric characteristics, the test environment conditions and level of activity. Additionally, manual measurements showed great brand-based differences between garments of the same specified size M (medium). Overall, the polyamide/elastane jersey was perceived as a better cycling outfit than the polyester outfit. The results of this study provide guidance for the optimal design and development of professional cyclist outfits. Clothing ; Perception ; Textile ; Sensation ; Psychology ; Materials science ; Composite material Textile materials and evaluations ; Ergonomics and Musculoskeletal Disorders ; Thermoregulation and physiological responses
Authors: Matthew J. Burn | Paul L. A. Popelier
Source: ChemRxiv (preprint, 2020-06-24)
Field: Materials Science — Materials Chemistry

Creating Gaussian Process Regression Models for Molecular Simulations Using Adaptive Sampling &lt;div&gt;FFLUX is a new force field that combines the accuracy of quantum mechanics with the speed of force &lt;/div&gt;&lt;div&gt;fields, without any link to the architecture of classical force fields. This force field is atom‐focused and &lt;/div&gt;&lt;div&gt;adopts the parameter‐free topological atom from Quantum Chemical Topology (QCT). FFLUX uses &lt;/div&gt;&lt;div&gt;Gaussian Process Regression (GPR) (aka kriging) models to make predicƟons of atomic properties, which &lt;/div&gt;&lt;div&gt;in this work are atomic energies according to QCT’s InteracƟng Quantum Atom (IQA) approach. Here &lt;/div&gt;&lt;div&gt;we report the adaptive sampling technique Maximum Expected Prediction Error (MEPE) to create data‐&lt;/div&gt;&lt;div&gt;compact, efficient and accurate kriging models (sub kJ mol‐1 for water, ammonia, methane and &lt;/div&gt;&lt;div&gt;methanol, and sub kcal mol‐1 for N‐methylacetamide (NMA)). The models cope with large molecular &lt;/div&gt;&lt;div&gt;distortions and are ready for use in molecular simulation. A brand new press‐one‐buƩon Python &lt;/div&gt;&lt;div&gt;pipeline, called ICHOR, carries out the training. &lt;/div&gt; Kriging ; Atom (system on chip) ; Force field (fiction) ; Physics ; Gaussian process ; Gaussian ; Computer science ; Mathematics ; Quantum mechanics ; Machine learning Machine Learning in Materials Science ; Metabolomics and Mass Spectrometry Studies ; Computational Drug Discovery Methods
Authors: Richard Couperthwaite | Douglas Allaire | Raymundo Arróyave
Source: Computational Materials Science (article, 2020-11-20)
Field: Materials Science — Metals and Alloys

Utilizing Gaussian processes to fit high dimension thermodynamic data that includes estimated variability CALPHAD ; Component (thermodynamics) ; Computer science ; Interface (matter) ; Stability (learning theory) ; Dimension (graph theory) ; Phase (matter) ; Thermodynamics ; Chemistry ; Mathematics ; Phase diagram ; Physics Hydrogen embrittlement and corrosion behaviors in metals ; Machine Learning in Materials Science ; High Temperature Alloys and Creep