jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Olena Soroka | Jacobus M. Sturm | Chris Lee | Herman Schreuders | B. Dam | F. Bijkerk
Source: International Journal of Hydrogen Energy (article, 2020-04-16)
Field: Materials Science — Materials Chemistry

Hydrogen diffusion through Ru thin films Hydrogen ; Ruthenium ; Diffusion ; Activation energy ; Atmospheric temperature range ; Analytical Chemistry (journal) ; Chemistry ; Reaction rate constant ; Thin film ; Fick's laws of diffusion ; Layer (electronics) ; Materials science ; Boltzmann constant ; Physical chemistry ; Kinetics ; Thermodynamics ; Catalysis ; Nanotechnology ; Physics ; Organic chemistry Hydrogen Storage and Materials ; Ammonia Synthesis and Nitrogen Reduction ; Catalysts for Methane Reforming
Authors: Katharina Kaiser | Johann Ewender | Frank Welle
Source: Polymers (article, 2020-12-15)
Field: Materials Science — Biomaterials

Recyclable Multilayer Packaging by Means of Thermoreversibly Crosslinking Adhesive in the Context of Food Law Lacking recyclability of multilayer packaging can be overcome by using a thermoreversible crosslinking adhesive consisting of maleimide- and furan-functionalized polyurethane-(PU-)prepolymers, reacting in a Diels-Alder-reaction. Here, the furan-functionalized PU-prepolymer carries furan-side-chains to avoid the usage of an additional crosslinking agent. Thus, <i>N</i>‑(2‑hydroxyethyl)maleimide and furfurylamine are the only two chemicals contained in the adhesive that are not listed in the appendix of EU Regulation 10/2011. Using migration modelling, it could be shown that, at 23 °C, both chemicals have lag-times of only a few minutes if 45 µm PE is used as a barrier. However, if the residual content is below 30 mg/kg, the legally specified maximum amount of 0.01 mg/kg food is not reached. After determining the diffusion coefficients and the activation energy of diffusion through ethylene-vinyl alcohol copolymer (EVOH), it could be determined that the lag-time of the migrants can be extended to at least 9 years by the use of 3 µm EVOH. From a food law point of view, the use of the described adhesive is possible if the above‑mentioned measures are complied. Maleimide ; Adhesive ; Furan ; Context (archaeology) ; Materials science ; Copolymer ; Polyurethane ; Polymer chemistry ; Food packaging ; Prepolymer ; Diffusion ; Activation energy ; Polymer science ; Chemical engineering ; Composite material ; Polymer ; Chemistry ; Organic chemistry ; Thermodynamics biodegradable polymer synthesis and properties ; Synthesis and properties of polymers ; Advanced Polymer Synthesis and Characterization
Authors: Yannis Vasilopoulos | Eliška Skořepová | Miroslav Šoóš
Source: Crystals (article, 2020-02-24)
Field: Materials Science — Materials Chemistry

COMF: Comprehensive Model-Fitting Method for Simulating Isothermal and Single-Step Solid-State Reactions It is well known that the implementation of the conventional model-fitting (CMF) method leads to several indistinguishable ‘best’ candidate models (BCMs) for a single-step isothermal solid-state reaction (ISSR), meaning that subjective selection becomes unavoidable. Here, we developed a more robust comprehensive model-fitting method (COMF) which, while maintaining the mathematical simplicity of CMF, utilizes a ranking criterion that enables automatic and unambiguous determination of the BCM. For each model evaluated, COMF, like CMF, fits the integral reaction rate, but, unlike CMF, it also fits the experimental conversion fraction and reaction speed. From this, three different determination coefficients are calculated and combined to rank the considered models. To validate COMF, we used two sets of experimental kinetic data from the literature regarding the isothermal desolvation of pharmaceutical solvates: (i) tetrahydrofuran solvates of sulfameter, and (ii) methanol solvates of ciclesonide. Our results suggest that from an algorithmic perspective, COMF could become the model-fitting method of choice for ISSRs making the selection of BCM easier and more reliable. Isothermal process ; Ranking (information retrieval) ; Computer science ; Rank (graph theory) ; Selection (genetic algorithm) ; Model selection ; Algorithm ; Applied mathematics ; Mathematics ; Thermodynamics ; Artificial intelligence ; Physics Thermal and Kinetic Analysis ; Chemistry and Chemical Engineering ; Computational Drug Discovery Methods
Authors: L. Lunéville | Philippe Garcia | David Siméone
Source: Physical Review Letters (article, 2020-02-26)
Field: Materials Science — Materials Chemistry

Predicting Nonequilibrium Patterns beyond Thermodynamic Concepts: Application to Radiation-Induced Microstructures In this work, we derive an analytical model to predict the appearance of all possible radiation-induced steady states and their associated microstructures in immiscible A_{c[over ¯]}B_{1-c[over ¯]} alloys, an example of a nonequilibrium dynamical system. This model is assessed against numerical simulations and experimental results which show that different microstructures characterized by the patterning of A-rich precipitates can emerge under irradiation. We demonstrate that the steady-state microstructure is governed by irradiation conditions and also by the average initial concentration of the alloy c[over ¯]. Such a dependence offers new leverage for tailoring materials with specific microstructures overcoming limitations imposed by the equilibrium thermodynamic phase diagram. Non-equilibrium thermodynamics ; Microstructure ; Materials science ; Phase diagram ; Thermodynamics ; Alloy ; Work (physics) ; Thermodynamic equilibrium ; Leverage (statistics) ; Irradiation ; Radiation ; Statistical physics ; Phase (matter) ; Physics ; Condensed matter physics ; Optics ; Metallurgy ; Nuclear physics ; Quantum mechanics ; Computer science Solidification and crystal growth phenomena ; Microstructure and mechanical properties ; High-pressure geophysics and materials
Authors: Lang Zhang | Liangliang Liu | Aiping Xiao | Siqi Huang | Defang Li
Source: Open Chemistry (article, 2020-12-16)
Field: Chemistry — Analytical Chemistry

Screening and analysis of xanthine oxidase inhibitors in jute leaves and their protective effects against hydrogen peroxide-induced oxidative stress in cells Abstract Jute ( Corchorus capsularis L.) is an annual herb of the bast fiber plant and has great potentials in food and medicinal usages because of its various bioactivities. In this study, ultrafiltration coupled with high-performance liquid chromatography-mass spectrometry was established for screening xanthine oxidase inhibitors from the jute leaves extract. Under the optimum screening conditions, three inhibitors were successfully screened and identified as chlorogenic acid, echinacoside, and isorhamnetin-rutinoside with UV and MS data. The fluorescent quenching analysis showed that three inhibitors quenched the fluorescence intensities of enzyme with different binding capacities. For further exploring the bioactivity of three inhibitors, the protective effects on hydrogen peroxide-induced oxidative stress was investigated using human normal liver cell (LO2), human gastric mucosal epithelial cell (GES-1), and human umbilical vein endothelial cell (HUVEC). As a result, they exhibited protective effects on three injured cells in dose-dependent manners without cytotoxicity. To evaluate the difference among different jute species obtained in our laboratories, the amounts of three compounds in ten samples were assessed and analyzed. The results showed that it could be divided into three groups. The jute leaves showed nutrient and medical potentials and deserved further research on pharmaceutical and biochemical utilization in future. Xanthine oxidase ; Hydrogen peroxide ; Oxidative stress ; Chemistry ; Bast fibre ; Chlorogenic acid ; Umbilical vein ; Biochemistry ; Enzyme ; Food science ; Traditional medicine ; Botany ; Biology ; Medicine Heavy Metals in Plants ; Gout, Hyperuricemia, Uric Acid ; Trace Elements in Health
Authors: Xin Chen | Yunyun Bian | Baichuan Mo | Peng Sun | Chunxia Chen | Jinsong Peng
Source: RSC Advances (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Copper(<scp>ii</scp>)-catalyzed synthesis of multisubstituted indoles through sequential Chan–Lam and cross-dehydrogenative coupling reactions Starting from arylboronic acids and ester (<i>Z</i>)-3-aminoacrylates, one-pot syntheses of diverse indole-3-carboxylic esters have been described through copper(ii)-catalyzed sequential Chan-Lam <i>N</i>-arylation and cross-dehydrogenative coupling (CDC) reactions. The initial Chan-Lam arylation can proceed in DMF at 100 °C for 24 h to give ester (<i>Z</i>)-3-(arylamino)acrylate intermediates in the presence of Cu(OAc)<sub>2</sub>/tri-<i>tert</i>-butylphosphine tetrafluoroborate, a catalytic amount of myristic acid as the additive, KMnO<sub>4</sub> and KHCO<sub>3</sub>. Sequentially, these <i>in situ</i> arylated intermediates can undergo an intramolecular oxidative cross-dehydrogenative coupling process in mixed solvents (DMF/DMSO = 2 : 1) at 130 °C to give C3-functionalized multi-substituted indole derivatives. Chemistry ; Indole test ; Catalysis ; Copper ; Acrylate ; Intramolecular force ; Medicinal chemistry ; Combinatorial chemistry ; Oxidative coupling of methane ; Tetrafluoroborate ; Organic chemistry ; Polymer chemistry ; Copolymer ; Ionic liquid Catalytic C–H Functionalization Methods ; Catalytic Cross-Coupling Reactions ; Synthesis and Catalytic Reactions
Authors: Pikee Priya | N. R. Aluru
Source: Journal of Power Sources (article, 2020-10-08)
Field: Materials Science — Materials Chemistry

A multiscale framework to predict electrochemical characteristics of yttrium doped Barium Zirconate based solid oxide cells Electrolyte ; Materials science ; Oxidizing agent ; Electrochemistry ; Oxide ; Electrode ; Yttrium ; Chemical engineering ; Analytical Chemistry (journal) ; Inorganic chemistry ; Chemical physics ; Chemistry ; Physical chemistry Advancements in Solid Oxide Fuel Cells ; Chemical Looping and Thermochemical Processes ; Catalysis and Oxidation Reactions
Authors: Pavani Surarapu | Janaki Rama Phanendra Kumar Ande | Aleena Varghese | Suman Reddy Mallipeddi | Dileep Reddy Goda | Sridhar Reddy Yerram | Swathi Kaluvakuri
Source: Asia Pacific Journal of Energy and Environment (article, 2020-12-31)
Field: Materials Science — Materials Chemistry

Quantum Dot Sensitized Solar Cells: A Promising Avenue for Next-Generation Energy Conversion By taking advantage of the unique qualities of colloidal quantum dots, quantum dot-sensitized solar cells (QDSSCs) provide a viable route for next-generation energy conversion while increasing the device's adaptability and light harvesting efficiency. This research aims to thoroughly examine the possibilities and difficulties associated with QDSSCs and offer information on their applications, methods for performance optimization, and policy ramifications. To assess the state-of-the-art research on QDSSCs, the technique systematically evaluates existing literature, including peer-reviewed articles, conference proceedings, and patents. Significant discoveries highlight developments in materials design, methods for fabricating devices, and potential integrations in consumer electronics, building-integrated photovoltaics, and off-grid applications. The policy implications underscore the necessity of regulatory frameworks to tackle environmental issues, set up guidelines and certification procedures, and foster global cooperation. In summary, this research highlights the importance of QDSSCs as a viable choice for sustainable energy conversion. It advocates for cooperative endeavors to surmount obstacles and expedite their integration into the renewable energy terrain. Quantum dot ; Renewable energy ; Photovoltaics ; Nanotechnology ; Computer science ; Certification ; Efficient energy use ; Systems engineering ; Photovoltaic system ; Risk analysis (engineering) ; Business ; Political science ; Engineering ; Materials science ; Electrical engineering Quantum Dots Synthesis And Properties ; TiO2 Photocatalysis and Solar Cells ; Advanced Photocatalysis Techniques
Authors: Jong Hyuk Lee
Source: Information Display (article, 2020-11-01)
Field: Materials Science — Materials Chemistry

QD Display: A Game‐Changing Technology for the Display Industry Abstract With its unprecedented picture quality, the QD display is poised to unveil a new horizon for the display industry. Here, Samsung Display Senior Vice President Jong Hyuk Lee explores its key characteristics. Key (lock) ; Display advertising ; Display device ; Advertising ; Computer graphics (images) ; Computer science ; Human–computer interaction ; Engineering ; Multimedia ; Business ; Computer security ; World Wide Web ; Operating system ; The Internet Quantum Dots Synthesis And Properties
Authors: Rebecca Lindsey | Laurence E. Fried | Nir Goldman | Sorin Bastea
Source: ChemRxiv (preprint, 2020-07-16)
Field: Materials Science — Materials Chemistry

Active Learning for Robust, High-Complexity Reactive Atomistic Simulations Machine learned reactive force fields based on polynomial expansions have been shown to be highly effective for describing simulations involving reactive materials. Nevertheless, the highly flexible nature of these models can give rise to a large number of candidate parameters for complicated systems. In these cases, reliable parameterization requires a well-formed training set, which can be difficult to achieve through standard iterative fitting methods. Here we present an active learning approach based on cluster analysis and Shannon information theory to enable semi-automated generation of informative training sets and robust machine learned force fields. Use of this tool is demonstrated for development of a model based on linear combinations of Chebyshev polynomials explicitly describing up to four-body interactions, for a chemically and structurally diverse system of C/O under extreme conditions. We show that this flexible training repository management approach enables development of models exhibiting excellent agreement with Kohn–Sham density functional theory (DFT) in terms of structure, dynamics, and speciation. Chebyshev polynomials ; Computer science ; Set (abstract data type) ; Chebyshev filter ; Algorithm ; Mathematics Machine Learning in Materials Science ; Topic Modeling ; Electronic and Structural Properties of Oxides
Authors: Erika Amemiya | Aaron Loo | Daniel G. Shlian | Gerard Parkin
Source: Chemical Science (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Rhenium <i>versus</i> cadmium: an alternative structure for a thermally stable cadmium carbonyl compound An alternative description is provided for the previously reported novel tetranuclear cadmium carbonyl compound, [Cd(CO)<sub>3</sub>(C<sub>6</sub>H<sub>3</sub>Cl)]<sub>4</sub>. Specifically, consideration of single crystal X-ray diffraction data indicates that the compound is better formulated as the rhenium compound, [Re(CO)<sub>3</sub>(C<sub>4</sub>N<sub>2</sub>H<sub>3</sub>S)]<sub>4</sub>. Furthermore, density functional theory calculations predict that, if it were to exist, [Cd(CO)<sub>3</sub>(C<sub>6</sub>H<sub>3</sub>Cl)]<sub>4</sub> would have a very different structure to that reported. While it is well known that X-ray diffraction may not reliably distinguish between atoms of similar atomic number (<i>e.g.</i> N/C and Cl/S), it is not generally recognized that two atoms with very different atomic numbers could be misassigned. The misidentification of two elements as diverse as Re and Cd (Δ<i>Z</i> = 27) is unexpected and serves as an important caveat for structure determinations. Rhenium ; Cadmium ; Chemistry ; Crystallography ; Inorganic chemistry ; Materials science ; Organic chemistry Organometallic Complex Synthesis and Catalysis ; Metal complexes synthesis and properties ; Magnetism in coordination complexes
Authors: Qinghui Meng | Lidong Zhang | Qinxue Chen | Yicheng Chi | Peng Zhang
Source: The Journal of Physical Chemistry A (article, 2020-09-28)
Field: Chemistry — Organic Chemistry

Influence of Torsional Anharmonicity on the Reactions of Methyl Butanoate with Hydroperoxyl Radical An ab initio chemical kinetics study of the reactions of methyl butanoate (MB) with hydroperoxyl radical (HO<sub>2</sub>) is presented in this paper. Particular interest is placed on determining the influences of torsional anharmonicity and addition reaction on the rate constants of hydrogen abstraction reactions. Stationary points on the potential energy surface of MB + HO<sub>2</sub> are calculated at the level of QCISD(T)/CBS//B3LYP/6-311++G(d,p). The transition state theory (TST) is used to calculate the high-pressure limit rate constants of the hydrogen abstraction reactions over a board range of temperature (500-2000 K). Anharmonicity of low-frequency torsional modes is considered in the rate calculations by using the one-dimensional hindered rotor approximation and the internal-coordinate multistructural approximation; the latter is used as a higher-level theoretical method to examine the applicability of the former in dealing with strongly coupled torsional modes. The calculated rate constants are compared with the available data from the literature and observed discrepancies are analyzed in detail. An energetically lowest-lying addition reaction with subsequent isomerization and decomposition reactions are identified on the potential energy surface. The multiple-well Master equation analysis shows that these reactions have a secondary influence on the rate constants in the temperature range of interest. Hydroperoxyl ; Anharmonicity ; Chemistry ; Photochemistry ; Organic chemistry ; Radical ; Physics ; Quantum mechanics Free Radicals and Antioxidants ; Biochemical effects in animals ; Molecular Spectroscopy and Structure
Authors: Wahyu Setyawan
Source: Journal of Applied Physics (article, 2020-10-09)
Field: Materials Science — Materials Chemistry

Density functional theory calculation of helium segregation and decohesion effect in W110/Ni111 interphase boundary Density functional theory is employed to study the preferential distribution and decohesion effect of He in a W–NiFe composite consisting of W particles embedded in an Ni-based solid solution matrix. A slab containing {110}⟨100⟩W//{111}⟨110⟩Ni interface is used as a surrogate model for the W–NiFe system. First, the fracture energy of the W/Ni interphase boundary (IB) (4.37 J/m2) is higher than the cleavage energy of Ni{111} (3.82 J/m2) and lower than the cleavage energy of W{110} (6.60 J/m2). The comparison shows that the cohesion of the IB is stronger than the Ni{111} planes that are away from the IB. However, the cohesion between the Ni{111} planes adjacent to the IB is found to be the weakest in this system, with a cleavage energy of 3.11 J/m2. Subsequently, the formation energy of He is calculated in the Ni slab, W slab, and various interstitial sites in the IB. The calculations show that He is significantly more stable in Ni than in W by about 1.75 eV. Interestingly, He does not prefer to segregate at the IB as compared to bulk Ni. Nevertheless, it prefers to segregate to the region between the Ni{111} planes adjacent to the IB and decreases the cohesion of the already weakest region. Based on an estimated amount of He gas production in 5 years under first wall neutron irradiation (neutron flux of 1.04 × 1015 n/cm2/s), He will decrease the cleavage energy of the weakest region by 21.2%, 15.4%, and 12.2% at 800, 1000, and 1200 °C, respectively. Interphase ; Cleavage (geology) ; Slab ; Materials science ; Density functional theory ; Helium ; Neutron ; Atomic physics ; Condensed matter physics ; Crystallography ; Composite material ; Physics ; Chemistry ; Fracture (geology) ; Nuclear physics ; Computational chemistry Fusion materials and technologies ; Nuclear Materials and Properties ; Advanced materials and composites
Authors: Thomas A. Logothetis | Colin M. Flowers
Source: Journal of Chemical Education (article, 2020-08-17)
Field: Chemistry — Physical and Theoretical Chemistry

Squaring the Circle by Attempting to Teach a Lab Class in the Cloud: Reflections after a Term in Lockdown Whether it is prolonged strike action, a protest movement, or a global viral outbreak, the disruptions triggered in higher education are profound. In a STEM subject, laboratory classes are vital to teaching and learning. Chemistry educators had to transport laboratory skills-based teaching and assessment of courses to the virtual world at short notice, while adhering to evolving university policies. Analysis of the situation from the perspective of the lecturer and the student revealed for a laboratory class setting that student engagement did not significantly change throughout the semester and was relatively high compared to other teaching activities. During the lockdown students embraced traditional pathways for seeking support and reluctantly adopted new opportunities presented to staff and students alike at the start of the closure period. More active and interactive formats failed to take proper hold mainly due to a combination of technology (restrictions in available bandwidth and hardware) and anxiety issues. Undergraduate students, however, do wish to engage with their studies, and if the difficulties identified herein can be addressed adequately, the scene can be set for a successful and supportive teaching and learning environment in a socially distanced lab class combined with improved online support. It would include a structured and prescribed participation in partly online, partly live teaching sessions that are summatively assessed. This must be supported by a formal induction to the available IT infrastructure as well as assurances that learning in open fora enriches the learning experience and should not cause nervousness. Sticking to the published timetable for synchronous delivery and additional asynchronous support opportunities will assist students in planning and undertaking a balanced workload, and the social aspects and value of face-to-face time in a blended teaching approach must be emphasized. Class (philosophy) ; Term (time) ; Mathematics education ; Cloud computing ; Science education ; Computer science ; Psychology ; Physics ; Artificial intelligence ; Astronomy Various Chemistry Research Topics ; Experimental Learning in Engineering ; Innovative Teaching Methods