jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Giselle Carvalho | Allyson Leandro Rodrigues dos Santos | Anízio M. Faria
Source: Journal of the Brazilian Chemical Society (article, 2022-01-01)
Field: Chemistry — Spectroscopy

Per-Aqueous Liquid Chromatography for the Separation of Polar Compounds-Preparation and Characterization of Poly(ethylene oxide-co-dimethylsiloxane) Based Stationary Phase Poly(ethylene oxide-co-dimethylsiloxane) was thermally immobilized on silica particles- Si(PEO)-to separate small polar compounds with water-rich mobile phases. Poly(ethylene oxideco- dimethylsiloxane) content on Si(PEO) stationary phase was optimized using a central composite design. Infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis morphologically and structurally characterized the optimized material. Separation of standard test mixtures showed that the Si(PEO) phase had a typical reversed-phase elution order. However, the Si(PEO) phase retained polar compounds better than C18 or aqueous C18 phases under waterrich mobile phases. Under this condition, small changes in the acetonitrile fraction resulted in a marked increase in the retention of some polar drugs on the Si(PEO) phase. A typical condition observed in per aqueous liquid chromatography separations, a more environmentally friendly liquid chromatography approach. On the other hand, hydrophobic compounds showed lower mass transfer rates due to their low solubility in the aqueous mobile phase. Thus, the Si(PEO) phase was more suitable and efficient for separating polar or hydrophilic compounds. Ethylene oxide ; Aqueous solution ; Thermogravimetric analysis ; Phase (matter) ; Acetonitrile ; Elution ; Materials science ; Chemistry ; Oxide ; Chemical engineering ; Chromatography ; Polymer ; Organic chemistry ; Copolymer Analytical Chemistry and Chromatography ; Mesoporous Materials and Catalysis ; Microfluidic and Capillary Electrophoresis Applications
Authors: Markus Schörner | Kerstin Mitländer | Moritz Wolf | Robert Franke | Marco Haumann
Source: ChemCatChem (article, 2022-05-19)
Field: Materials Science — Polymers and Plastics

Silicon Carbide Supported Liquid Phase (SLP) Hydroformylation Catalysis – Effective Reaction Kinetics from Continuous Gas‐phase Operation Abstract The hydroformylation reaction is one of the most important applications of homogeneous catalysis on an industrial scale with worldwide production capacities exceeding 15 Mio tons per year. Efficient catalyst immobilization becomes mandatory for such large‐scale processes. In this work, a supported liquid phase (SLP)‐type catalyst on a silicon carbide support material was applied in the continuous Rh‐bpp (bpp=biphephos) catalyzed gas‐phase hydroformylation of but‐1‐ene. A parameter variation was carried out in the pressure range from 0.5 to 3.0 bara for but‐1‐ene, 0.5 to 5 bara for H 2 , 0.5 to 5 bara for CO, and in the temperature range from 90 to 125 °C. Activation energies were determined for the individual reactions showing a shift in activation energy most significantly for the hydroformylation to n ‐pentanal for temperatures of 110 °C and above. For all substrates the effective reaction orders were calculated and employed in a power‐law rate model giving good agreement of measured and modeled data within a ±20 % error margin. Similar results were obtained using a microkinetic model. Hydroformylation ; Catalysis ; Chemistry ; Carbide ; Silicon carbide ; Phase (matter) ; Activation energy ; Reaction rate ; Homogeneous catalysis ; Chemical kinetics ; Physical chemistry ; Thermodynamics ; Kinetics ; Chemical engineering ; Rhodium ; Organic chemistry ; Physics Polymer Foaming and Composites ; Carbon dioxide utilization in catalysis ; Injection Molding Process and Properties
Authors: Andoni Ugartemendia | Aran García-Lekue | Elisa Jimenez‐Izal
Source: Scientific Reports (article, 2022-07-29)
Field: Materials Science — Materials Chemistry

Tailoring magnetism in silicon-doped zigzag graphene edges Recently, the edges of single-layer graphene have been experimentally doped with silicon atoms by means of scanning transmission electron microscopy. In this work, density functional theory is applied to model and characterize a wide range of experimentally inspired silicon doped zigzag-type graphene edges. The thermodynamic stability is assessed and the electronic and magnetic properties of the most relevant edge configurations are unveiled. Importantly, we show that silicon doping of graphene edges can induce a reversion of the spin orientation on the adjacent carbon atoms, leading to novel magnetic properties with possible applications in the field of spintronics. Zigzag ; Magnetism ; Graphene ; Doping ; Silicon ; Materials science ; Condensed matter physics ; Nanotechnology ; Optoelectronics ; Physics ; Mathematics ; Geometry Graphene research and applications ; Quantum and electron transport phenomena ; Advancements in Battery Materials
Authors: Cristian Zagar | Ferdinand G. P. Krammer | J. B. Pendry | Alexei A. Kornyshev
Source: Nanoscale Horizons (article, 2022-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Optical response of hyperbolic metamaterials with adsorbed nanoparticle arrays Experimental studies of have been recently performed to determine the optical effect of adsorption of arrays of gold nanoparticles, NPs (16 nm or 40 nm in diameter) on reflective substrates (Ma <i>et al.</i>, <i>ACS Photonics</i>, 2018, <b>5</b>, 4604-4616; Ma <i>et al.</i>, <i>ACS Nano</i>, 2020, <b>14</b>, 328-336) and on transparent interfaces (Montelongo <i>et al.</i>, <i>Nat. Mater.</i>, 2017, 16, 1127-1135). As predicted by the theory (Sikdar <i>et al.</i>, <i>Phys. Chem. Chem. Phys.</i>, 2016, <b>18</b>, 20486-20498), a reflection quenching effect was observed on the reflective substrates, in the frequency domain centred around the nanoparticle localised plasmon resonance. Those results showed a broad dip in reflectivity, which was deepening and red-shifting with increasing array densities. In contrast, the second system has shown, also in accordance with the theory (Sikdar and Kornyshev, <i>Sci. Rep.</i>, 2016, <b>6</b>, 1-16), a broad reflectivity peak in the same frequency domain, increasing in intensity and shifting to the red with densification of the array. In the present paper, we develop a theory of an optical response of NP arrays adsorbed on the surface of stacked nanosheet hyperbolic substrates. The response varies between quenched and enhanced reflectivity, depending on the volume fractions of the metallic and dielectric components in the hyperbolic metamaterial. We reproduce the results of the earlier works in the two opposite limiting cases - of a pure metal and a pure dielectric substrates, while predicting novel resonances for intermediate compositions. Whereas the metal/dielectric ratio in the hyperbolic substrate cannot be changed in time - for each experiment a new substrate should be fabricated - the density of the adsorbed nanoparticle arrays can be controlled in real time in electrochemical photonic cells (Montelongo <i>et al.</i>, <i>Nat. Mater.</i>, 2017, <b>16</b>, 1127-1135; Ma <i>et al.</i>, <i>ACS Photonics</i>, 2018, <b>5</b>, 4604-4616; Ma <i>et al.</i>, <i>ACS Nano</i>, 2020, <b>14</b>, 328-336). Therefore, we systematically study the effect of the array density on the optical response of such systems, which could be later verified experimentally. We also investigate the manifestation of these findings in a hyperbolic-Fabry-Perot cell. Metamaterial ; Nanoparticle ; Materials science ; Adsorption ; Nanotechnology ; Optics ; Physics ; Optoelectronics ; Chemistry ; Physical chemistry Metamaterials and Metasurfaces Applications ; Antenna Design and Analysis ; Orbital Angular Momentum in Optics
Authors: Gaël Privault | Guénolé Huitric | Marius Hervé | Elżbieta Trzop | Julien Tranchant | B. Corraze | Zohra Khaldi | Laurent Cario | Étienne Janod | Jean-Claude Ameline | Nicolas Godin | Roman Bertoni
Source: The European Physical Journal Special Topics (article, 2022-10-11)
Field: Materials Science — Polymers and Plastics

Ultrafast photo-induced dynamics of $$\hbox {V}_{2} \hbox {O}_{3}$$ thin films under hydrostatic pressure Femtosecond ; Hydrostatic pressure ; Ultrashort pulse ; Materials science ; Brillouin zone ; Phase transition ; Hydrostatic equilibrium ; Spectroscopy ; Optoelectronics ; Optics ; Laser ; Physics ; Condensed matter physics ; Thermodynamics Transition Metal Oxide Nanomaterials ; Porphyrin and Phthalocyanine Chemistry ; Photosynthetic Processes and Mechanisms
Authors: Mohosena Begum Tanu | Arun Chandra Barman | Mohammad Ferdous Siddque | Sonia Sku | Md. Nazmul Hossen | Paul C. Southgate | Yahia Mahmud
Source: Journal of Shellfish Research (article, 2022-04-18)
Field: Materials Science — Biomaterials

Impact of Culture Period on Quality of Image Pearls Produced by the Freshwater Mussel, Lamellidens marginalis, in Bangladesh Pearls are gems produced by biological processes within the living tissues of molluscs. Image pearls are a form of blister pearl that portray a design or image such as a bird, fish, flower, goddess, etc. To achieve this, a paraffin wax mold is inserted between the shell and the mantle of a freshwater mussel and subsequent nacre coverage produces an image pearl after an appropriate culture period for the mussel. The optimum culture period has not yet been determined to maximize the quality of image pearls produced in Bangladesh, and this knowledge gap was addressed in this study. Image pearl production using the freshwater mussel Lamellidens marginalis was conducted over three culture periods (T 1 = 7 mo, T 2 = 9 mo, and T 3 = 11 mo). A total of 3,150 mussels were implanted with 2.5 × 1.5 cm2 paraffin wax molds, with 1,050 mussels allocated to each treatment, which had five replicates. Survival and pearl production rate of mussels were negatively correlated with culture period. Survival and pearl production rate were 14.7%, 12.3%, and 11.9% for mussels cultured for 7, 9, and 11 mo, respectively. The thicknesses of the nacre making up the image pearl and pearl luster were both improved with longer culture periods. The highest quality pearls with a mean nacre thickness of 0.71 mm were produced after 11 mo. Pearls produced after 11 mo also had the highest luster (40.05 lux) compared with pearls cultured for 7 mo (12.85 lux) or 9 mo (30.2 lux). There were statistically significant differences at the P < 0.05 level in survival rate F (2, 12) = 9.40, P = 0.004 and nacre layer thickness F (2, 12) = 13.30, P = 0.001 between T 1 and T 3. The results indicated that image pearls with high luster and improved quality are produced after longer culture durations and confirms the influence of culture period on image pearl production and quality. Further research is required to improve image pearl production methods and pearl yield. Mussel ; Pearl ; Biology ; Fishery ; Aquaculture ; Fish <Actinopterygii> Calcium Carbonate Crystallization and Inhibition ; Aquatic Invertebrate Ecology and Behavior ; Environmental Toxicology and Ecotoxicology
Authors: Madhuparna Karmakar | Subhojit Roy | Shantanu Mukherjee | Rajesh Narayanan
Source: Physical Review Research (article, 2022-12-05)
Field: Materials Science — Materials Chemistry

Disorder stabilized breached-pair phase in an <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>s</mml:mi></mml:math>-wave superconductor The breached-pair state wherein superconductivity coexists with magnetic polarization is known to exist as a ground state of an imbalanced Fermi system only under very fine-tuned conditions. Here, we show that an s-wave superconductor that is well described by a spin-selectively disordered attractive Hubbard model away from half filling has the breached-pair state as a ground-state without the need for such fine-tuning. The existence of this breached-pair phase is established by laying recourse to a Monte Carlo technique called static path approximation (SPA). Further, by using the SPA, we map out the entire phase diagram of the spin-selectively disordered attractive Hubbard model and show that apart from the breached-pair phase, the many-body system hosts the putative s-wave superconducting state and a polarized Fermi-liquid state. Phase diagram ; Ground state ; Superconductivity ; Condensed matter physics ; Physics ; Hubbard model ; Fermi liquid theory ; Phase (matter) ; Quantum mechanics Electronic and Structural Properties of Oxides ; Physics of Superconductivity and Magnetism ; Iron-based superconductors research
Authors: Yifan Lu | Jie Xu | Jun Jiang | Rongru Zhang | Honghao Yue | Qiang Zhang | Yuanzi Zhou
Source: Engineering Research Express (article, 2022-07-12)
Field: Materials Science — Materials Chemistry

A new model-free control method for SMA wire actuators based on DRL Abstract Shape memory alloy (SMA) has been widely used in different applications due to its unique shape memory property. However, when used as an actuator, it exhibits a hysteresis behavior in its relation between temperature and strain, which is highly nonlinear and difficult to control. Although studies have been conducted on establishing various constitutive models of SMA, it is still difficult to achieve the precise control of the SMA wire with the existing models. In this work, a new promising approach regarding the SMA control task as a reinforcement learning (RL) problem is proposed to address this issue, which does not require accurate mathematical models. Both RL and an improved method named deep reinforcement learning (DRL) are used to solve the problem of precise control of a 1D SMA wire actuator, respectively. The simulation results indicate that with the DRL method, the agent can precisely control the output deformation of the SMA wire after only ten episodes of training. Compared with the DRL method, the RL agent can also achieve the same training target but with hundreds of training. SMA* ; Shape-memory alloy ; Actuator ; Computer science ; Reinforcement learning ; Hysteresis ; Nonlinear system ; Property (philosophy) ; Control theory (sociology) ; Task (project management) ; Control engineering ; Control (management) ; Artificial intelligence ; Engineering ; Algorithm ; Physics Shape Memory Alloy Transformations
Authors: Jiaqin Wang | V.B.C. Tan
Source: Materials (article, 2022-07-14)
Field: Materials Science — Polymers and Plastics

Effects of Relative Positions of Defect to Inclusion on Nanocomposite Strength It is generally accepted that material inhomogeneity causes stress concentrations at the interface and thus reduces the overall strength of a composite. To overcome this reduction in strength, some groups experimented on coating the nanoinclusions with a layer of rubbery material, aiming for higher energy absorption. However, representative volume element (RVE) nanocomposite models, established with randomly distributed core-shell nanoparticles and single nanoparticle cells, show that the enhancement in strength observed in some experiments remains elusive computationally. By including a pre-existing crack in the matrix of the RVE, the stress concentration at the crack tip is reduced for cases where the nanoparticle and precrack are aligned away from the loading direction. This suggests that stress concentrations around inherent defects in materials can sometimes be reduced by adding nanoparticles to improve material strength. The effect is reversed if the crack and nanoparticle are aligned towards the loading direction. Parametric studies were also carried out in terms of the relative stiffness of the nanoparticle to the matrix and crack length. Validation tests were performed on 3D RVEs with an elliptical crack as the initial defect, and the results match with the 2D findings. Nanocomposite ; Inclusion (mineral) ; Materials science ; Composite material ; Mineralogy ; Chemistry Polymer Nanocomposites and Properties ; Polymer Nanocomposite Synthesis and Irradiation ; Polymer crystallization and properties
Authors: Woon‐Shing Yeung | Fu-Sui Hung | Van-Phung Mai | Ruey‐Jen Yang
Source: Journal of Mechanics (article, 2022-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Analytical solution of cloaking in creeping flow inside composite porous media with simultaneous heat transfer ABSTRACT This paper presents a theoretical analysis of steady-state creeping flow in a composite porous domain with coupling heat transfer. The problem arises in thermal cloaking studies in which it is desirable to hide an obstacle from the surrounding hydrodynamic and thermal fields, by suitably covering the obstacle with a cloak having specific material properties. The particular system under investigation consists of a porous composite region, with a thermal-hydro field driven by imposed temperature and pressure difference in the surrounding. Both two dimensional circular and three-dimensional axisymmetric spherical annuli are considered. Under the validity of Darcy law for a porous medium, an exact solution satisfying the continuity, momentum and energy equations at any Péclet number is derived. The analytical results have been numerically verified using the commercial code COMSOL. Cloaking ; Porous medium ; Mechanics ; Heat transfer ; Obstacle ; Materials science ; Poromechanics ; Darcy's law ; Composite number ; Rotational symmetry ; Porosity ; Classical mechanics ; Physics ; Composite material ; Metamaterial ; Law Metamaterials and Metasurfaces Applications ; Thermal Radiation and Cooling Technologies ; Acoustic Wave Phenomena Research
Authors: Massimiliano Delferro | Katherine McCullough | Daniel S. King | Saumil Chheda | Magali Ferrandon | Timothy A. Goetjen | Zoha H. Syed | Trent R. Graham | Nancy Washton | Omar K. Farha | Laura Gagliardi
Source: ChemRxiv (preprint, 2022-11-30)
Field: Chemistry — Inorganic Chemistry

High-Throughput Experimentation, Theoretical Modeling, and Human Intuition: Lessons Learned in Metal-Organic Framework-Supported Catalyst Design We have screened an array of 23 metals deposited onto the metal–organic framework (MOF) NU-1000 for propyne dimerization to hexadienes under different reaction conditions for a total of ~1400 experiments. By a first-of-its-kind study utilizing data-driven algorithms and high-throughput experimentation (HTE) in MOF catalysis, yields on Cu-deposited NU-1000 were improved from 4.2% to 24.4%. Characterization of the most-performant catalysts reveal conversion to hexadiene to be due to the formation of large Cu nanoparticles, which is further supported by reaction mechanisms calculated with density functional theory (DFT). Our results demonstrate both the strengths and weaknesses of the HTE approach. As a strength, HTE excels at being able to find interesting and novel catalytic activity; any a priori theoretical approach would be hard-pressed to find success, as high-performing catalysts required highly specific operating conditions difficult to model theoretically, and initial naïve single-atom models of the active site did not prove representative of the nanoparticle catalysts responsible for conversion to hexadiene. As a weakness, our results show how the HTE approach must be designed and monitored carefully to find success; in our initial campaign (~six months and over half of the total experiments conducted) only minor catalytic performances (up to 4.2% yield) were achieved, which was only improved following a complete overhaul of our HTE approach and questioning our initial assumptions. Thus, the HTE approach is much less automated than it may seem, even if driven by machine learning algorithms – one must carefully design their HTE campaign to find success. Catalysis ; Intuition ; A priori and a posteriori ; Throughput ; Nanoparticle ; Computer science ; Yield (engineering) ; Density functional theory ; Nanotechnology ; Phenomenology (philosophy) ; Materials science ; Process engineering ; Chemistry ; Engineering ; Computational chemistry ; Organic chemistry ; Metallurgy Metal-Organic Frameworks: Synthesis and Applications ; Machine Learning in Materials Science ; Catalytic Processes in Materials Science
Authors: Bojana Ranković | Ryan‐Rhys Griffiths | Henry B. Moss | Philippe Schwaller
Source: ChemRxiv (preprint, 2022-12-06)
Field: Materials Science — Materials Chemistry

Bayesian optimisation for additive screening and yieldimprovements in chemical reactions – beyond one-hot encodings Reaction additives play a significant role in controlling the reactivity and outcome of chemical reactions. For example, a recent high-throughput additive screening identified a phthalimide ligand additive Ni-catalysed photoredox decarboxylative arylations. This discovery enabled a 4-fold yield improvement by stabilising oxidative addition complexes and breaking up deactivated catalyst aggregates. However, such large-scale screenings are currently inaccessible to most research groups. This work demonstrates how these discoveries can be made under much lower experimental budgets using Bayesian optimisation. We consider a unique reaction screening setting with 720 additives which forces us to go beyond simple one-hot encoding of the reaction components. We investigate a range of molecular representations and demonstrate convincing improvements over baselines. Our approach is not limited to Ni-catalysed reactions but can be generally applied to, for example, achieving yield improvements in diverse cross-coupling reactions or unlocking access to new chemical spaces of interest to the chemical and pharmaceutical industries. Presented at ELLIS Workshop on Machine Learning for Molecules (ML4Molecules 2022). Yield (engineering) ; Bayesian probability ; Combinatorial chemistry ; Catalysis ; Phthalimide ; Computer science ; Chemistry ; Bayesian inference ; Fine chemical ; Reactivity (psychology) ; Biochemical engineering ; Organic chemistry ; Artificial intelligence ; Materials science ; Engineering Machine Learning in Materials Science ; Radical Photochemical Reactions ; CO2 Reduction Techniques and Catalysts
Authors: Kyungtae Lee | Mukil V. Ayyasamy | Yangfeng Ji | Prasanna V. Balachandran
Source: Research Square (preprint, 2022-02-24)
Field: Materials Science — Materials Chemistry

A Comparison of Explainable Artificial Intelligence Methods in the Phase Classification of Multi-Principal Element Alloys Abstract We demonstrate the capabilities of two model-agnostic local post hoc model interpretability methods, namely breakDown (BD) and shapley (SHAP), to explain the predictions of a black-box classification learning model that establishes a quantitative relationship between chemical composition and multi-principal element alloys phase formation. We trained an ensemble of support vector machines using a dataset with 1,821 instances, 12 features with low pair-wise correlation, and seven phase labels. Feature contributions to the model prediction are computed by BD and SHAP for each composition. The resulting BD and SHAP transformed data are then used as inputs to identify similar composition groups using k-means clustering. Explanation-of-clusters by features reveal that the results from SHAP agree more closely with the literature. Visualization of compositions within a cluster using Ceteris-Paribus (CP) profile plots show the functional dependencies between the feature values and predicted response. Despite the differences between BD and SHAP in variable attribution, only minor changes were observed in the CP profile plots. Explanation-of-clusters by examples show that the clusters that share a common phase label contain similar compositions, which clarifies the similar-looking CP profile trends. In the limits of a dataset with independent and non-interacting features, SHAP and BD appear to capture similar pattern. Principal component analysis ; Interpretability ; Feature (linguistics) ; Cluster analysis ; Pattern recognition (psychology) ; Artificial intelligence ; Cluster (spacecraft) ; Phase (matter) ; Computer science ; Similarity (geometry) ; Transformation (genetics) ; k-nearest neighbors algorithm ; Mathematics ; Chemistry ; Image (mathematics) Machine Learning in Materials Science ; Hydrogen embrittlement and corrosion behaviors in metals ; Nuclear Materials and Properties