jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Xiong Jun | Yuan Wang | Guoming Ma | Qiang Zhang | Shusheng Zheng
Source: Sensors (article, 2018-07-26)
Field: Materials Science — Materials Chemistry

Field Applications of Ultra High Frequency Techniques for Defect Detection in GIS The reliable and stable operation of power apparatus is important for the development of GIS. It is important to utilize condition monitoring technologies and anticipate possible failures in advance. Many papers have been published about the partial discharge detection with UHF or X-ray in laboratory, but seldom in field application. Thus, many engineers at project sites are not familiar with the current professional diagnosis techniques. Recently, during the GIS routine data analysis obtained by partial discharge online monitoring system, it was found that the UHF monitoring signals' developing trend of the 220 kV GIS No. 2 high-voltage side of transformer in phase C at an actual station was abnormal and needed further detection. In order to precisely investigate the problem and then guide the operation and maintenance activities, a series of professional diagnoses were conducted. Three new types of partial discharge detection and positioning methods were applied for accuracy, including UHF partial discharge detection based on multi-stage amplified signal demodulation and multiple weighted averages processing; the partial discharge detection based on the signal radiation hole of insulation disk at the ground connection; and the positioning method based on UHF-SHF. After a series of troubleshooting works, the partial discharge defects have been diagnosed, and the case can be referred in the field monitoring of GIS. Partial discharge ; Ultra high frequency ; Troubleshooting ; Switchgear ; Computer science ; Demodulation ; SIGNAL (programming language) ; Transformer ; High voltage ; Field (mathematics) ; Electrical engineering ; Electronic engineering ; Voltage ; Remote sensing ; Engineering ; Reliability engineering ; Geology High voltage insulation and dielectric phenomena ; Geophysical Methods and Applications ; Power Transformer Diagnostics and Insulation
Authors: Alberto Cingolani | Tommaso Casalini | Stefano Caimi | Antoine Klaue | Mattia Sponchioni | Filippo Rossi | Giuseppe Perale
Source: Preprints.org (preprint, 2018-07-03)
Field: Materials Science — Biomaterials

A Methodologic Approach for the Selection of Bio-Resorbable Polymers in the Development of Medical Devices: The Case of Poly(L-lactide-&lt;em&gt;co&lt;/em&gt;-e-caprolactone) In the last decades bioresorbable and biodegradable polymers have gained a very good reputation both in research and in industry thanks to their unique characteristics. They are, indeed, able to ensure high performances and biocompatibility, at the same time avoiding post-healing surgical interventions for devices removal. In the medical device industrial use of such biopolymers, it is widely known that product formulation and manufacturing need to follow specific procedures in order to ensure both proper mechanical properties and desired degradation profile. Moreover, also the sterilization method is crucial and its impact on physical properties is generally underestimated. In this work we focused our attention on the effect of different terminal sterilization methods on two commercially available poly(L-lactide-co-&amp;epsilon;-caprolactone) with equivalent chemical composition (70% PLA and 30% PCL) and relatively similar initial molecular weight, but different chains arrangement and crystallinity. Results obtained show that crystallinity plays a key role, helping in preserving the narrow distribution of chains and, as a consequence, defined physical properties. These statements can be used as guidelines for a better choice of the most adequate biodegradable polymers in the production of resorbable medical devices. Crystallinity ; Biocompatibility ; Biodegradable polymer ; Caprolactone ; Polymer ; Lactide ; Polyester ; Materials science ; Biochemical engineering ; Biomedical engineering ; Composite material ; Medicine ; Engineering biodegradable polymer synthesis and properties ; Additive Manufacturing and 3D Printing Technologies ; Bone Tissue Engineering Materials
Authors: Lifen Zhang | Fusheng Chen | Wen Zhang | Qian Wu
Source: Journal of Chemistry (article, 2018-05-28)
Field: Chemistry — Organic Chemistry

Kinetics and Characteristics of Soybean Oil and Protein Extracted by AOT Reverse Micelle Technology The mass transfer process of soybean oil extracted by AOT reverse micelle was determined. Meanwhile, the physicochemical properties of oil and structural properties of protein were also investigated by gas chromatography (GC), Fourier infrared spectrum (FTIR), and amino acid analyzer. The results indicated that the mass transfer model can be set up as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn fontstyle="italic">1</mml:mn><mml:mo>+</mml:mo><mml:mn fontstyle="italic">2</mml:mn><mml:mo stretchy="false">(</mml:mo><mml:mn fontstyle="italic">1</mml:mn><mml:mo>-</mml:mo><mml:mi>x</mml:mi><mml:mo stretchy="false">)</mml:mo><mml:mo>-</mml:mo><mml:mn fontstyle="italic">3</mml:mn><mml:msup><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mn fontstyle="italic">1</mml:mn><mml:mo>-</mml:mo><mml:mi>x</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mrow><mml:mn fontstyle="italic">2</mml:mn><mml:mo>/</mml:mo><mml:mn fontstyle="italic">3</mml:mn></mml:mrow></mml:msup><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.248</mml:mn><mml:mo>•</mml:mo><mml:mrow><mml:mrow><mml:mi mathvariant="normal">exp</mml:mi></mml:mrow><mml:mo>⁡</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mo>-</mml:mo><mml:mn fontstyle="italic">720.8</mml:mn><mml:mo>/</mml:mo><mml:mi>T</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mo>•</mml:mo><mml:mi>t</mml:mi></mml:math>. The reaction probably belongs to internal diffusion. The oil extracted by AOT reverse micelle was in better quality according to physicochemical analysis. The soybean protein almost retained its original structure in AOT reverse micelle by FTIR and amino acid analysis. Therefore, AOT reverse micelle is an attractive procedure for extracting oil and protein simultaneously. Chemistry Surfactants and Colloidal Systems ; Protein Interaction Studies and Fluorescence Analysis ; Diffusion Coefficients in Liquids
Authors: Francis M. Gaitho | Mesfin Tsige | Genene Tessema Mola | Giuseppe Pellicane
Source: Polymers (article, 2018-03-15)
Field: Materials Science — Materials Chemistry

Surface Segregation of Cyclic Chains in Binary Melts of Thin Polymer Films: The Influence of Constituent Concentration We carry out extensive molecular dynamics simulations of thin films of bead-spring models of binary mixtures composed of cyclic and linear polymer chains. We study the equilibrium behavior of the polymer chains for two very different chain lengths, which resemble short (10-mers) and long (100-mers) chains, at different concentrations of the binary mixture. We clearly show how the concentration variable affects the enrichment of either of the two polymer species at the interface, and also how the chain length influences this process. Polymer ; Materials science ; Binary number ; Chain (unit) ; Chemical physics ; Chemical engineering ; Molecular dynamics ; Thin film ; Polymer chemistry ; Thermodynamics ; Chemistry ; Nanotechnology ; Computational chemistry ; Composite material Material Dynamics and Properties ; Phase Equilibria and Thermodynamics ; Rheology and Fluid Dynamics Studies
Authors: Xinfang Jin | Anthony Y. Ku | Atul Verma | Brandon Ohara | Kevin Huang | Surinder Singh
Source: Journal of The Electrochemical Society (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

The Performance of Syngas-Fueled SOFCs Predicted by a Reduced Order Model (ROM): Temperature and Fuel Composition Effects An electrochemical reduced order model (ROM) has been developed in this study to simulate the performance of syngas-fueled anode-supported SOFCs with coupled bulk chemical reactions and multi-species gas diffusion in the electrodes.Experimental V-I curves with syngas fuel were used to validate the model to ensure its high fidelity.The model was used to investigate the effects of fuel composition and temperature on the electrochemical performance of the cell, chemical reaction rate and concentration distributions of gaseous species across the anode.The results show that H 2 electro-oxidation dominates the overall cell performance, and that CO contributes to the performance indirectly via water gas shift (WGS) reaction, especially at low CO:H 2 ratio and low current densities.Increasing the temperature enhances the performance of syngas-fueled SOFCs by increasing the rates of total electrochemical oxidation and the WGS reaction.The present work provides fundamental knowledge and framework for future performance simulations of large-scale and more complex syngas-fueled SOFC systems. Syngas ; Anode ; Electrochemistry ; Gas composition ; Chemical engineering ; Work (physics) ; Diffusion ; Partial oxidation ; Materials science ; Chemistry ; Thermodynamics ; Catalysis ; Electrode ; Physical chemistry ; Organic chemistry Advancements in Solid Oxide Fuel Cells ; Electrocatalysts for Energy Conversion ; Electronic and Structural Properties of Oxides
Authors: М. А. Орлова | А. Л. Николаев | Т. П. Трофимова | А. П. Орлов | А. В. Северин | Stepan N. Kalmykov
Source: Bulletin of Russian State Medical University (article, 2018-12-24)
Field: Materials Science — Materials Chemistry

Hydroxyapatite and porphyrin-fullerene nanoparticles for diagnostic and therapeutic delivery of paramagnetic ions and radionuclides Nanoparticles for drug delivery are the subject of extensive research. Importantly, they can transform in size during synthesis or actual use, thereby changing their cytotoxic properties. The aim of the present work was to study the tendency of [67Zn] porphyrin-fullerene nanoparticles (BFNP) to aggregate over time and to compare the properties of hydroxyapatite (HAP) nanoparticles obtained through 3 different techniques. We found that aggregation of BFNP nanoparticles does not affect their function but attenuates their cytotoxicity against leukemia cells. We were also able to obtain HAP nanoparticles with programmable properties (such as size, shape or the capacity to adsorb metal ions, ligands and chemical complexes) through enzymatic synthesis by varying its conditions. The synthesized HAP nanoparticles contain short-lived isotopes of zinc and copper (in the form of ions and complexes with pyrimidine or thiazine derivatives). These tumoricidal components (a radionuclide and a ligand or a complex) determine the diagnostic and therapeutic potential of the obtained radiopharmaceutical agents. Nanoparticle ; Porphyrin ; Fullerene ; Metal ions in aqueous solution ; Chemistry ; Adsorption ; Cytotoxicity ; Drug delivery ; Materials science ; Combinatorial chemistry ; Ion ; Nanotechnology ; Nuclear chemistry ; Photochemistry ; Organic chemistry Diamond and Carbon-based Materials Research ; Fullerene Chemistry and Applications ; Boron Compounds in Chemistry
Authors: Laith A. Algharagholy | Thomas Pope | Colin J. Lambert
Source: Journal of Physics Condensed Matter (article, 2018-01-17)
Field: Materials Science — Materials Chemistry

Strain-induced bi-thermoelectricity in tapered carbon nanotubes We show that carbon-based nanostructured materials are a novel testbed for controlling thermoelectricity and have the potential to underpin the development of new cost-effective environmentally-friendly thermoelectric materials. In single-molecule junctions, it is known that transport resonances associated with the discrete molecular levels play a key role in the thermoelectric performance, but such resonances have not been exploited in carbon nanotubes (CNTs). Here we study junctions formed from tapered CNTs and demonstrate that such structures possess transport resonances near the Fermi level, whose energetic location can be varied by applying strain, resulting in an ability to tune the sign of their Seebeck coefficient. These results reveal that tapered CNTs form a new class of bi-thermoelectric materials, exhibiting both positive and negative thermopower. This ability to change the sign of the Seebeck coefficient allows the thermovoltage in carbon-based thermoelectric devices to be boosted by placing CNTs with alternating-sign Seebeck coefficients in tandem. Seebeck coefficient ; Thermoelectric effect ; Carbon nanotube ; Thermoelectric materials ; Materials science ; Nanotechnology ; Carbon fibers ; Condensed matter physics ; Optoelectronics ; Composite material ; Thermal conductivity ; Thermodynamics ; Composite number ; Physics Advanced Thermoelectric Materials and Devices ; Molecular Junctions and Nanostructures ; Graphene research and applications
Authors: Joshua J. Sutton | Jonathan E. Barnsley | Joseph I. Mapley | Paweł Wagner | David L. Officer | Keith C. Gordon
Source: Molecules (article, 2018-02-14)
Field: Chemistry — Physical and Theoretical Chemistry

Modulation of Donor-Acceptor Distance in a Series of Carbazole Push-Pull Dyes; A Spectroscopic and Computational Study A series of eight carbazole-cyanoacrylate based donor-acceptor dyes were studied. Within the series the influence of modifying the thiophene bridge, linking donor and acceptor and a change in the nature of the acceptor, from acid to ester, was explored. In this joint experimental and computational study we have used electronic absorbance and emission spectroscopies, Raman spectroscopy and computational modeling (density functional theory). From these studies it was found that extending the bridge length allowed the lowest energy transition to be systematically red shifted by 0.12 eV, allowing for limited tuning of the absorption of dyes using this structural motif. Using the aforementioned techniques we demonstrate that this transition is charge transfer in nature. Furthermore, the extent of charge transfer between donor and acceptor decreases with increasing bridge length and the bridge plays a smaller role in electronically mixing with the acceptor as it is extended. Acceptor ; Carbazole ; Density functional theory ; Photochemistry ; Thiophene ; Chemistry ; Absorbance ; Absorption spectroscopy ; Raman spectroscopy ; Materials science ; Computational chemistry ; Organic chemistry ; Optics Photochemistry and Electron Transfer Studies ; Photochromic and Fluorescence Chemistry ; Conducting polymers and applications
Authors: Claudia Draxl | Matthias Scheffler
Source: MRS Bulletin (preprint, 2018-09-01)
Field: Materials Science — Materials Chemistry

NOMAD: The FAIR concept for big data-driven materials science Big data ; Data science ; Raw data ; Center of excellence ; Field (mathematics) ; Computer science ; Data sharing ; Analytics ; Excellence ; Identification (biology) ; Data mining ; Database ; Political science Machine Learning in Materials Science ; Advanced X-ray and CT Imaging ; Mineral Processing and Grinding
Authors: Madeline Van Winkle | David Scrymgeour | Bryan Kaehr | J.J. Reczek
Source: Advanced Materials (article, 2018-03-30)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Laser Rewritable Dichroics through Reconfigurable Organic Charge‐Transfer Liquid Crystals Charge-transfer materials based on the self-assembly of aromatic donor-acceptor complexes enable a modular organic-synthetic approach to develop and fine-tune electronic and optical properties, and thus these material systems stand to impact a wide range of technologies. Through laser-induction of temperature gradients, in this study, user-defined patterning of strongly dichroic and piezoelectric organic thin films composed of donor-acceptor columnar liquid crystals is shown. Fine, reversible control over isotropic versus anisotropic regions in thin films is demonstrated, enabling noncontact writing/rewriting of micropolarizers, bar codes, and charge-transfer based devices. Materials science ; Acceptor ; Thin film ; Laser ; Optoelectronics ; Charge (physics) ; Dichroic glass ; Liquid crystal ; Nanotechnology ; Optics ; Condensed matter physics Liquid Crystal Research Advancements ; Advanced Materials and Mechanics ; Photochromic and Fluorescence Chemistry
Authors: Chun‐Fai Ng | Hak‐Fun Chow | Thomas C. W. Mak
Source: Angewandte Chemie (article, 2018-03-02)
Field: Materials Science — Biomaterials

Halogen‐Bond‐Mediated Assembly of a Single‐Component Supramolecular Triangle and an Enantiomeric Pair of Double Helices from 2‐(Iodoethynyl)pyridine Derivatives Abstract Construction of single‐component supramolecular triangle and unprecedented spontaneous resolution of pairs of intertwined supramolecular 3 1 ‐ and 3 2 ‐double helices by the self‐assembly of achiral 2‐(iodoethynyl)pyridine and its derivatives have been achieved through intermolecular ethynyl C−I⋅⋅⋅⋅N halogen bonds in the crystalline state. Fine‐tuning of the molecular structure of the achiral monomer and choice of solvents for crystallization have a dominant effect on the resultant supramolecular architectures. Supramolecular chemistry ; Pyridine ; Chemistry ; Intermolecular force ; Monomer ; Halogen bond ; Supramolecular assembly ; Crystallography ; Enantiomer ; Crystallization ; Halogen ; Self-assembly ; Supramolecular chirality ; Stereochemistry ; Double bond ; Molecule ; Hydrogen bond ; Polymer chemistry ; Crystal structure ; Organic chemistry ; Alkyl ; Polymer Supramolecular Self-Assembly in Materials ; Crystallography and molecular interactions ; Supramolecular Chemistry and Complexes
Authors: Jayaprakash Ajay | Sriram Shirisha | Masatoshi Ishida | Kosuke Ito | Shigeki Mori | Hiroyuki Furuta | Sabapathi Gokulnath
Source: Chemistry - A European Journal (article, 2018-12-27)
Field: Materials Science — Materials Chemistry

Planar Antiaromatic Core‐Modified 24π Hexaphyrin(1.0.1.0.1.0) and 32π Octaphyrin(1.0.1.0.1.0.1.0) Bearing Alternate Hybrid Diheterole Units The Lewis acid catalyzed self-condensation of hybrid diheterole (furan-pyrrole and thiophene-pyrrole) precursors has afforded novel Hückel antiaromatic 24π hexaphyrin(1.0.1.0.1.0) and 32π octaphyrin(1.0.1.0.1.0.1.0) structures without β-annulated bridges. Single-crystal X-ray diffraction analysis of the hybrid porphyrinoids (S<sub>3</sub> N<sub>3</sub> -ox and O<sub>4</sub> N<sub>4</sub> -ox) revealed a nearly planar conformation and the <sup>1</sup> H NMR spectra suggest the presence of paratropic ring currents. These antiaromatic macrocycles show characteristic optical features and underwent reversible two-electron reduction to Hückel aromatic 26π- and 34π-electron species, respectively, as is evident from the results of spectroscopic and theoretical studies (nucleus-independent chemical shift (NICS) and anisotropy of the current-induced density (ACID) calculations). The incorporation of hybrid diheteroles alternately into expanded porphyrin skeletons provides a novel approach to the fine-tuning of the electronic structures of planar antiaromatic macrocycles. Antiaromaticity ; Pyrrole ; Chemistry ; Crystallography ; Ring (chemistry) ; Furan ; Porphyrin ; Thiophene ; Aromaticity ; Stereochemistry ; Photochemistry ; Molecule ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Synthesis and Properties of Aromatic Compounds ; Photosynthetic Processes and Mechanisms
Authors: Keisuke Sudoh | Ko Furukawa | Haruyuki Nakano | Soji Shimizu | Yoshihiro Matano
Source: Heteroatom Chemistry (article, 2018-11-26)
Field: Materials Science — Materials Chemistry

Synthesis and properties of redox‐switchable zinc complexes of 10,15,20‐triaryl‐15‐aza‐5‐oxaporphyrin Abstract The synthesis, aromaticity, and optical and electrochemical properties of zinc(II) complexes of 10,15,20‐triaryl‐15‐aza‐5‐oxaporphyrin (TriAAOP) were investigated. Metal‐templated cyclization of a zinc(II) 1,19‐dichloro‐5,10,15‐triaryl‐10‐azatetrapyrrin complex with an oxygen source afforded 20π TriAAOP in the neutral form. Oxidation of 20π TriAAOP with silver (I) hexafluorophosphate generated the 19π radical cation or 18π dication depending on the content of oxidant used. The interconversion between the three oxidation states (18π, 19π, and 20π) resulted in distinct changes in the aromaticity and optical properties of the 15‐aza‐5‐oxaporphyrin π‐system. Nuclear magnetic resonance spectroscopy of 20π TriAAOP revealed its antiaromatic character, whereas that of the 18π TriAAOP dication showed its aromatic character. The combined effect of the two meso ‐heteroatoms was directly reflected in the redox properties of the porphyrin ring; TriAAOP was reduced more easily and more difficult to oxidize than the zinc(II) complex of 5,10,15,20‐tetraaryl‐5,15‐diaz‐aporphyrin (TADAP). In the ultraviolet‐visible‐near–infrared spectra of the materials, the lowest‐energy electronic excitations of the 19π and 18π TriAAOP derivatives were considerably red‐shifted compared with those of the isoelectronic TADAP derivatives. Based on the results of density functional theory calculations, it was concluded that the observed differences between TriAAOP and TADAP would arise from the high electronegativity of oxygen; specific frontier orbitals of the TriAAOP π‐systems were energetically stabilized relative to those of the TADAP π‐system. The present findings corroborate that the meso ‐modification of a porphyrin rings with different kinds of heteroatoms is a promising strategy to fine tune their light‐response properties that are switchable by reversible single electron transfer processes. Chemistry ; Dication ; Aromaticity ; Electronegativity ; Antiaromaticity ; Zinc ; Heteroatom ; Redox ; Photochemistry ; Density functional theory ; Ring (chemistry) ; Inorganic chemistry ; Molecule ; Computational chemistry ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Luminescence and Fluorescent Materials ; Synthesis and Properties of Aromatic Compounds