jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Łukasz G. Łukasiewicz | Matt Rammo | Charlie Stark | Maciej Krzeszewski | Denis Jacquemin | Aleksander Rebane | Daniel T. Gryko
Source: ChemPhotoChem (article, 2020-02-23)
Field: Materials Science — Materials Chemistry

Ground‐ and Excited‐State Symmetry Breaking and Solvatofluorochromism in Centrosymmetric Pyrrolo[3,2‐<i>b</i>]pyrroles Possessing two Nitro Groups Abstract Six centrosymmetric pyrrolo[3,2‐ b ]pyrroles possessing either two nitro or two CF 3 SO 2 strong electron‐withdrawing groups have been synthesized in a straightforward manner from simple building blocks and their one and two‐photon properties investigated. Although two‐photon absorption maxima clearly correspond to the S 0 →S 2 transition, there is always a considerable shoulder at the region related to the S 0 →S 1 transition. This fact clearly points to a small degree of symmetry breaking in the ground state which becomes more prevalent in the excited state. The systems showing the strongest excited‐state symmetry breaking have also been identified by first principles calculations. Both experimental data and theoretical calculations (performed with time‐dependent density functional theory) have revealed that changing the degree of conjugation between the nitro−aryl substituents and the core enables fine‐tuning of not only emission wavelengths but also the solvent dependent fluorescence intensity. Although there is no charge‐transfer between electron‐withdrawing 4‐cyanophenyl substituents located on nitrogen atoms and the core, nevertheless, their presence modifies the absorption and emission maxima. These groups also enable a record high fluorescence quantum yield in toluene (0.97) to be reached. By probing ground‐state symmetry by two‐photon absorption and excited‐state symmetry by solvatofluorochromism, we are able to obtain insight regarding the pathway of the molecule during and after the electronic transition. Excited state ; Ground state ; Chemistry ; Density functional theory ; Molecular symmetry ; Absorption (acoustics) ; Symmetry breaking ; Nitro ; Atomic physics ; Molecule ; Molecular physics ; Photochemistry ; Computational chemistry ; Materials science ; Physics ; Quantum mechanics ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Photochemistry and Electron Transfer Studies ; Nonlinear Optical Materials Studies
Authors: Paolo Tecilla | Davide Bonifazi
Source: ChemistryOpen (review, 2020-05-01)
Field: Materials Science — Materials Chemistry

Configurational Selection in Azobenzene‐Based Supramolecular Systems Through Dual‐Stimuli Processes Azobenzene is one of the most studied light-controlled molecular switches and it has been incorporated in a large variety of supramolecular systems to control their structural and functional properties. Given the peculiar isomeric distribution at the photoexcited state (PSS), azobenzene derivatives have been used as photoactive framework to build metastable supramolecular systems that are out of the thermodynamic equilibrium. This could be achieved exploiting the peculiar <i>E</i>/<i>Z</i> photoisomerization process that can lead to isomeric ratios that are unreachable in thermal equilibrium conditions. The challenge in the field is to find molecular architectures that, under given external circumstances, lead to a given isomeric ratio in a reversible and predictable manner, ensuring an ultimate control of the configurational distribution and system composition. By reviewing early and recent works in the field, this review aims at describing photoswitchable systems that, containing an azobenzene dye, display a controlled configurational equilibrium by means of a molecular recognition event. Specifically, examples include programmed photoactive molecular architectures binding cations, anions and H-bonded neutral guests. In these systems the non-covalent molecular recognition adds onto the thermal and light stimuli, equipping the supramolecular architecture with an additional external trigger to select the desired configuration composition. Azobenzene ; Photoisomerization ; Supramolecular chemistry ; Molecular switch ; Metastability ; Chemical physics ; Molecular dynamics ; Chemistry ; Materials science ; Molecule ; Nanotechnology ; Isomerization ; Computational chemistry ; Organic chemistry Photochromic and Fluorescence Chemistry ; Supramolecular Self-Assembly in Materials ; Photoreceptor and optogenetics research
Authors: Paul Galanopoulo | Pierre‐Yves Dugas | Muriel Lansalot | Franck D’Agosto
Source: Polymer Chemistry (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Poly(ethylene glycol)-<i>b</i>-poly(vinyl acetate) block copolymer particles with various morphologies <i>via</i> RAFT/MADIX aqueous emulsion PISA The polymerization-induced self-assembly (PISA) of amphiphilic diblock copolymers of poly(ethylene glycol)-<italic>b</italic>-poly(vinyl acetate) in water was achieved through macromolecular design <italic>via</italic> interchange of xanthate (MADIX) polymerization in emulsion. Copolymer ; Raft ; Vinyl acetate ; Ethylene glycol ; Polymer chemistry ; Emulsion polymerization ; Polymerization ; Xanthate ; Amphiphile ; Aqueous solution ; Emulsion ; Chemistry ; Chain transfer ; Reversible addition−fragmentation chain-transfer polymerization ; Materials science ; Radical polymerization ; Organic chemistry ; Polymer Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems ; Polymer Surface Interaction Studies
Authors: Dmytro Bederak | Dmitry N. Dirin | Nataliia Sukharevska | Jamo Momand | Maksym V. Kovalenko | Maria Antonietta Loi
Source: Chemistry of Materials (article, 2020-12-10)
Field: Materials Science — Materials Chemistry

S-Rich PbS Quantum Dots: A Promising p-Type Material for Optoelectronic Devices PbS colloidal quantum dots (CQDs) are versatile building blocks for bottom-up fabrication of various optoelectronic devices. The transport properties of thin films of this class of materials depend on the size of the CQDs, their surface ligands, and stoichiometry. The most common synthetic methods yield PbS CQDs with an excess of Pb atoms, which induces n-type transport properties in CQD films. In this work, we developed a new synthesis, which offers S-rich PbS CQDs. Thanks to their sufficient colloidal stability in nonpolar solvents, we established a protocol for the integration of these CQDs into thin field-effect transistors and found strong hole-dominated transport with a hole mobility of about 1 × 10&lt;sup&gt;-2&lt;/sup&gt; cm&lt;sup&gt;2&lt;/sup&gt;/Vs. Moreover, we were able to enhance the electron mobility for almost two orders of magnitude while keeping the hole mobility nearly the same. This approach allows us to obtain reliably p-doped PbS CQDs, which can be used for the fabrication of various electronic and optoelectronic devices. Fabrication ; Materials science ; Electron mobility ; Quantum dot ; Optoelectronics ; Doping ; Nanotechnology ; Colloid ; Transistor ; Chemistry ; Physics Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Copper-based nanomaterials and applications
Authors: Chu-Yu Huang | Hung-Che Hsiao
Source: Sensors (article, 2020-12-10)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Integrated EC-SERS Chip with Uniform Nanostructured EC-SERS Active Working Electrode for Rapid Detection of Uric Acid Toxemia of pregnancy is a very dangerous disease for pregnant women. The mortality rate of toxemia of pregnancy is close to 10% to 15%. Early detection of pregnancy toxemia is to monitoring uric acid concentration in urine. The current mainstream method for detecting uric acid requires an enzyme (urate oxidase), which needs to be stored in a low-temperature environment, and the method requires complex chemical steps, which takes a longer time and more samples. In this study, we propose an integrated miniature three-electrode electrochemical surface-enhanced Raman spectroscopy chip (EC-SERS chip) suitable for rapid EC-SERS detection applications. The integrated microfluidic reservoir on the chip makes it easy to use, which is very suitable for rapid detection applications. The SERS active working electrode for the proposed integrated EC-SERS chip is a nanocone array polycarbonate (PC) substrate decorated with an evenly distributed and tightly packed array of gold nanospheres. It showed good uniformity and can be easily reproduced. The integrated EC-SERS chip is very small compared to the traditional electrochemical cell, which reduces the sample volume required for the testing. In addition, the chip is for one-time use only. It eliminates the need to clean electrochemical cells for reuse, thereby reducing the possibility of contamination and inaccurate detection. Various low-concentration Rhodamine 6G (R6G) solutions were tested to verify the performance of the developed EC-SERS chip. Experimental results showed that the proposed EC-SERS chip has a strong enhancement factor of up to 8.5 × 10<sup>6</sup> and a very good EC-SERS uniformity (the relative standard deviation of EC-SERS intensity is as low as 1.41%). The EC-SERS chip developed has been further tested for the detection of uric acid in synthetic urine. The results showed that the EC-SERS signal intensity has a highly linear relationship with the logarithm of the uric acid concentration in synthetic urine, which indicates that the developed EC-SERS chip is suitable for the quantitative detection of uric acid in synthetic urine. Therefore, the developed EC-SERS chip is very promising to be used in routine and early diagnosis of pregnancy toxemia and may be used in many other medical tests, food safety, and biotechnology applications. Electrode ; Chip ; Lab-on-a-chip ; Materials science ; Nanotechnology ; Uric acid ; Rhodamine 6G ; Working electrode ; Electrochemistry ; Microfluidics ; Chemistry ; Computer science ; Telecommunications Gold and Silver Nanoparticles Synthesis and Applications ; Electrochemical Analysis and Applications ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: Rumeysa Bilginer | Dilce Ozkendir‐Inanc | Ümit Hakan Yıldız | Ahu Arslan Yıldız
Source: Journal of Applied Polymer Science (article, 2020-11-24)
Field: Materials Science — Biomaterials

Biocomposite scaffolds for <scp>3D</scp> cell culture: Propolis enriched polyvinyl alcohol nanofibers favoring cell adhesion Abstract The objective of this work is generation of propolis/polyvinyl alcohol (PVA) scaffold by electrospinning for 3D cell culture. Here, PVA used as co‐spinning agent since propolis alone cannot be easily processed by electrospinning methodology. Propolis takes charge in maximizing biological aspect of scaffold to facilitate cell attachment and proliferation. Morphological analysis showed size of the electrospun nanofibers varied between 172–523 nm and 345–687 nm in diameter, for non‐crosslinked and crosslinked scaffolds, respectively. Incorporation of propolis resulted in desired surface properties of hybrid matrix, where hybrid scaffolds highly favored protein adsorption. To examine cell compatibility, NIH‐3T3 and HeLa cells were seeded on propolis/PVA hybrid scaffold. Results confirmed that integration of propolis supported cell adhesion and cell proliferation. Also, results indicated electrospun propolis/PVA hybrid scaffold provide suitable microenvironment for cell culturing. Therefore, developed hybrid scaffold could be considered as potential candidate for 3D cell culture and tissue engineering. Propolis ; Polyvinyl alcohol ; Electrospinning ; Nanofiber ; Scaffold ; Materials science ; Adhesion ; Tissue engineering ; Biocomposite ; Cell adhesion ; Chemistry ; Nanotechnology ; Composite material ; Polymer ; Biomedical engineering ; Composite number ; Food science Electrospun Nanofibers in Biomedical Applications ; Electrohydrodynamics and Fluid Dynamics ; Bee Products Chemical Analysis
Authors: Daiki Misonou | Kento Sasaki | Shuntaro Ishizu | Yasuaki Monnai | Kohei M. Itoh | Eisuke Abe
Source: AIP Advances (article, 2020-02-01)
Field: Materials Science — Materials Chemistry

Construction and operation of a tabletop system for nanoscale magnetometry with single nitrogen-vacancy centers in diamond A single nitrogen-vacancy (NV) center in diamond is a prime candidate for a solid-state quantum magnetometer capable of detecting single nuclear spins with prospective application to nuclear magnetic resonance (NMR) at the nanoscale. Nonetheless, an NV magnetometer is still less accessible to many chemists and biologists as its experimental setup and operational principle are starkly different from those of conventional NMR. Here, we design, construct, and operate a compact tabletop-sized system for quantum sensing with a single NV center, built primarily from commercially available optical components and electronics. We show that our setup can implement state-of-the-art quantum sensing protocols that enable the detection of single 13C nuclear spins in diamond and the characterization of their interaction parameters, as well as the detection of a small ensemble of proton nuclear spins on the diamond surface. This article provides extensive discussions on the details of the setup and the experimental procedures, and our system will be reproducible by those who have not worked on the NV centers previously. Spins ; Magnetometer ; Diamond ; Quantum sensor ; Quantum ; Nanoscopic scale Diamond and Carbon-based Materials Research ; Magnetic Field Sensors Techniques ; Atomic and Subatomic Physics Research
Authors: Muhammad Usman Tariq | Muhammad Haseeb | Mohammed Aledhari | Rehma Razzak | Reza M. Parizi | Fahad Saeed
Source: IEEE Access (article, 2020-12-25)
Field: Chemistry — Spectroscopy

Methods for Proteogenomics Data Analysis, Challenges, and Scalability Bottlenecks: A Survey Big Data Proteogenomics lies at the intersection of high-throughput Mass Spectrometry (MS) based proteomics and Next Generation Sequencing based genomics. The combined and integrated analysis of these two high-throughput technologies can help discover novel proteins using genomic, and transcriptomic data. Due to the biological significance of integrated analysis, the recent past has seen an influx of proteogenomic tools that perform various tasks, including mapping proteins to the genomic data, searching experimental MS spectra against a six-frame translation genome database, and automating the process of annotating genome sequences. To date, most of such tools have not focused on scalability issues that are inherent in proteogenomic data analysis where the size of the database is much larger than a typical protein database. These state-of-the-art tools can take more than half a month to process a small-scale dataset of one million spectra against a genome of 3 GB. In this article, we provide an up-to-date review of tools that can analyze proteogenomic datasets, providing a critical analysis of the techniques' relative merits and potential pitfalls. We also point out potential bottlenecks and recommendations that can be incorporated in the future design of these workflows to ensure scalability with the increasing size of proteogenomic data. Lastly, we make a case of how high-performance computing (HPC) solutions may be the best bet to ensure the scalability of future big data proteogenomic data analysis. Proteogenomics ; Computer science ; Scalability ; Big data ; Workflow ; Proteomics ; Genomics ; Process (computing) ; Computational biology ; Genome ; Data science ; Data mining ; Database ; Biology Advanced Proteomics Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Genomics and Phylogenetic Studies
Authors: N. Zebouchi | A. Haddad
Source: Energies (review, 2020-12-04)
Field: Materials Science — Materials Chemistry

A Review on Real-Size Epoxy Cast Resin Insulators for Compact High Voltage Direct Current Gas Insulated Switchgears (GIS) and Gas Insulated Transmission Lines (GIL)—Current Achievements and Envisaged Research and Development Due to the ever-increasing demand for electricity in the one hand and the environmental constraints to use clean energy on the other hand, the global production of energy from remote renewable sources, particularly from large hydropower plants and offshore wind farms and their connection to the grid are expected to grow significantly in the future. Consequently, the demand to carry this electric power by high voltage direct current (HVDC) technology will increase too. The most suitable HVDC power transmission technology to deliver large amounts of power, exceeding a capacity of 5 GW per bipolar system over long distances with lower losses is by using compact HVDC gas insulated transmission lines (DC GIL) and gas insulated switchgears (DC GIS) with rated voltage (maximum continuous operating voltage) of ±550 kV and 5000 A which are presently under development worldwide. Among the critical challenges for the development of these HVDC gas insulated systems, there are the epoxy cast resin insulators that are used to separate gas compartments also called spacers. Indeed, thorough research studies have been and still being carried out to well understand and clarify the electrical insulation characteristics of HVDC spacers using mainly cylindrical samples and small insulator models, where useful results have been obtained and proposed for implementation in real compact gas insulated systems. However, few practical investigations have been undertaken on real size spacers (product scale) to verify such research outcomes and validate the reliability of the spacers to collect experiences or for commercial use. This paper reviews the current achievements of real size HVDC spacers development. It describes the basic electric field calculation and spacers design, the verification of the insulation performance and validation testing. It gives today’s commercially available compact HVDC GIS/GIL and finally it presents the envisaged future research and development. Switchgear ; Electric power transmission ; Electrical engineering ; Insulator (electricity) ; Voltage ; High-voltage direct current ; High voltage ; Power transmission ; Electricity ; Direct current ; Engineering ; Automotive engineering ; Environmental science ; Power (physics) ; Physics High voltage insulation and dielectric phenomena ; Thermal Analysis in Power Transmission ; Electrical Fault Detection and Protection
Authors: Flávio José de Oliveira Morais | Pedro Carvalhaes-Dias | Luís F. C. Duarte | Anderson Wedderhoff Spengler | Kleber Vieira de Paiva | Thiago Martins | Andreu Cabot | José Siqueira Dias
Source: Energies (article, 2020-05-06)
Field: Materials Science — Materials Chemistry

Optimization of the TEGs Configuration (Series/Parallel) in Energy Harvesting Systems with Low-Voltage Thermoelectric Generators Connected to Ultra-Low Voltage DC–DC Converters Solar radiation and human activity generate ubiquitous temperature gradients that could be harvested by thermoelectric generators (TEGs). However, most of these temperature gradients are in the range of very few degrees and, while TEGs are able to harvest them, the resulting output voltages are extremely small (a few hundreds of mV), and DC–DC converters are necessary to boost them to usable levels. Impedance matching between TEGs and DC–DC converter plays a fundamental role in the energy harvesting efficiency. Therefore, it is essential to determine the output power of the system in different configurations, in order to decide on the optimum TEG connection. Here, we present an electronic circuit to measure the maximum power that can be harvested with low-voltage TEGs connected to a DC–DC converter. The developed circuit is an electronic controlled load that drains the maximum current from the output of the DC–DC converter while maintaining its output voltage at the maximum allowed value. Using a mechanical set-up able to apply precise low temperature gradients between the hot and cold side of the TEGs, experimental data using different configurations of TEGs are obtained. The measured results show that, for ultra-low voltages, the TEG ensemble’s output impedance plays an important role not only in the amount of the energy scavenged, but also in the onset temperature of the energy harvesting. Materials science ; Converters ; Voltage ; Thermoelectric generator ; Energy harvesting ; Low voltage ; Power (physics) ; Electrical engineering ; Output impedance ; Maximum power principle ; Impedance matching ; Electrical impedance ; Computer science ; Thermoelectric effect ; Physics ; Engineering Advanced Thermoelectric Materials and Devices ; Innovative Energy Harvesting Technologies ; Energy Harvesting in Wireless Networks
Authors: Anthony Wang | Ryan Murdock | Steven Kauwe | Anton O. Oliynyk | Aleksander Gurlo | Jakoah Brgoch | Kristin A. Persson | Taylor D. Sparks
Source: ChemRxiv (preprint, 2020-05-06)
Field: Materials Science — Materials Chemistry

Machine Learning for Materials Scientists: An Introductory Guide Towards Best Practices This Editorial is intended for materials scientists interested in performing machine learning-centered research.We cover broad guidelines and best practices regarding the obtaining and treatment of data, feature engineering, model training, validation, evaluation and comparison, popular repositories for materials data and benchmarking datasets, model and architecture sharing, and finally publication.In addition, we include interactive Jupyter notebooks with example Python code to demonstrate some of the concepts, workflows, and best practices discussed.Overall, the data-driven methods and machine learning workflows and considerations are presented in a simple way, allowing interested readers to more intelligently guide their machine learning research using the suggested references, best practices, and their own materials domain expertise. Best practice ; Computer science ; Benchmarking ; Workflow ; Python (programming language) ; Data science ; Feature engineering ; Software engineering ; Artificial intelligence ; Deep learning ; Programming language ; Database Machine Learning in Materials Science ; Computational Drug Discovery Methods ; X-ray Diffraction in Crystallography
Authors: Seyma Kokyay | Enes Kılınç | Fatih Uysal | Hüseyin Kurt | Erdal Çelik | Muharrem Düğenci
Source: Engineering Science and Technology an International Journal (article, 2020-05-15)
Field: Materials Science — Materials Chemistry

A prediction model of artificial neural networks in development of thermoelectric materials with innovative approaches The fact that the properties of thermoelectric materials are to be estimated with Artificial Neural Networks without production and measurement will help researchers in terms of time and cost. For this purpose, figure of merit, which is the performance value of thermoelectric materials, is estimated by Artificial Neural Networks without an experimental study. P-and n-type thermoelectric bulk samples were obtained in 19 different compositions by doping different elements into Ca2.7Ag0.3Co4O9- and Zn0.98Al0.02O-based oxide thermoelectric materials. The Seebeck coefficient, electrical resistivity and thermal diffusivity values of the bulk samples were measured from 200 °C to 800 °C with an increase rate of 100 °C, and figure of merit values were calculated. 7 different Artificial Neural Network models were created using 123 measured results of experimental data and the molar masses of the doping elements. In this system aiming to predict the electrical resistivity, thermal diffusivity and figure of merit values of thermoelectric materials, the average R value and accuracy rate of these values were estimated to be 94% and 80%, respectively. Thermoelectric effect ; Thermal diffusivity ; Figure of merit ; Artificial neural network ; Materials science ; Thermoelectric materials ; Seebeck coefficient ; Electrical resistivity and conductivity ; Doping ; Thermal conductivity ; Thermodynamics ; Composite material ; Machine learning ; Computer science ; Optoelectronics ; Physics ; Electrical engineering ; Engineering Advanced Thermoelectric Materials and Devices ; Gas Sensing Nanomaterials and Sensors ; Thermal Radiation and Cooling Technologies