jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Vinu Kumar Shettahalli Mantaiah | C. Sasikumar | E. Sakthivelmurugan | J. P. Rishi
Source: Materiali in tehnologije (article, 2021-12-10)
Field: Materials Science — Polymers and Plastics

EFFECT OF SALT-WATER AGING ON THE MECHANICAL PROPERTIES OF FLAX-WOVEN FABRIC-REINFORCED EPOXY COMPOSITES In this investigation four varieties of plain derived-irregular basket-woven-flax fabric-reinforced epoxy (F-E) composites pre-treated with alkali and trimethoxymethylsilane (ATS) were prepared with a hand lay-up process by varying their weight fraction of fiber loadings (0; 25; 35; 45) w/%. A water-absorption test (salt water) as per ASTM D 570-98 was performed over the fabricated composites and studied its consequences on their static mechanical properties (such as tensile, flexural, impact and interlaminar shear strength) in accordance with the ASTM standards. The results revealed that salt-water-soaked ATS-treated F-E composites exhibited poorer mechanical properties than unsoaked ones. Moreover, this study elaborated the kinetics of water absorption and showed that the moisture-absorption rate depends on the weight fraction of fibre content. Furthermore, scanning electron microscopy (SEM) disclosed fiber splittings and severe damage at the fiber-matrix interface as experienced by soaked F-E composites. Materials science ; Composite material ; Absorption of water ; Epoxy ; Ultimate tensile strength ; Flexural strength ; Fiber ; Scanning electron microscope ; Mass fraction ; Moisture ; Izod impact strength test Textile materials and evaluations ; Natural Fiber Reinforced Composites ; Mechanical Behavior of Composites
Authors: Weihua Wang | Duhui Lu | Xiang Li | Lin Liang
Source: Processes (article, 2021-08-21)
Field: Materials Science — Metals and Alloys

Risk Assessment and Material Suitability Evaluation on Static Equipment of Hydrofluoric Acid Alkylation Unit In 2005, a 60 kt/a alkylation (ALK) unit began to resume production in the Second Oil Refinery Plant of Beijing Yanshan Petrochemical Company. There have been many leak cases from pipeline welds, valve body, flange, etc. After a half-year period of operation, production process is stable. However, the operation of the hydrofluoric (HF) acid ALK unit has been suffered from corrosion problems. There are no clear answers and references to the following problems. What types of corrosion are currently in the main equipment for HF acid ALK unit? What does cause equipment corrosion? What are the main influencing factors for corrosion? What measures can be taken to reduce the corrosion of HF acid? In this paper, considering the acid-related conditions of the ALK unit, the damage mechanism and damage rate analysis were carried out to calculate the safety risk of the static equipment of the ALK unit. Based on the damage mechanism and failure history, the material suitability of the ALK unit was investigated. The anti-corrosion measures and recommended materials for important corrosion parts of the ALK unit were proposed. It is meaningful for reducing the number of shutdowns of ALK units and maintaining safe and stable operation of the unit. Corrosion ; Refinery ; Petrochemical ; Hydrofluoric acid ; Flange ; Unit (ring theory) ; Environmental science ; Forensic engineering ; Waste management ; Engineering ; Materials science ; Metallurgy ; Structural engineering ; Mathematics Hydrogen embrittlement and corrosion behaviors in metals ; Concrete Corrosion and Durability ; Smart Materials for Construction
Authors: Martino Aldrigo | Mircea Dragoman | Nicola Pelagalli | Emiliano Laudadio | L. Zappelli | S. Iordănescu | D. Vasilache | Adrian Dinescu | Luca Pierantoni | Pierluigi Stipa | Davide Mencarelli
Source: IEEE Transactions on Microwave Theory and Techniques (article, 2021-12-03)
Field: Materials Science — Materials Chemistry

Microwave Detection Using Two-Atom-Thick Self-Switching Diodes Based on Quantum Simulations and Advanced Circuit Models In this article, a two-atom-thick diode based on 2-D materials is presented for microwave detection. The diode consists of a molybdenum disulfide monolayer/graphene monolayer heterojunction transferred onto a silicon/silicon dioxide substrate and patterned by means of nanolithography techniques to obtain a geometrical self-switching diode. The interaction between the two monolayers gives rise to a double-stage device, which behaves as a back-to-back diode in the [−3, +3] V voltage range, and as a tunnel diode when exceeding +10 V. The heterojunction can be reproduced at the wafer scale, thanks to its CMOS compatibility and ease of fabrication, and it can be used efficiently as a microwave detector up to 10 GHz, with the best performance around the ISM 2.45-GHz band. Starting from advanced quantum simulations to predict the dc behavior of the single heterojunction-based channel, the diode was fabricated and fully characterized experimentally. Lastly, a rigorous equivalent circuit model is provided, which relies on the measured scattering parameters at high frequencies and allows treating the diode embedded into a coplanar waveguide line as a two-port lossy device. This way, the device can be exploited in circuit-based numerical tools for the design of complex microwave front ends. Optoelectronics ; Materials science ; Diode ; Step recovery diode ; PIN diode ; Microwave ; Coplanar waveguide ; Schottky diode ; Computer science ; Telecommunications 2D Materials and Applications ; Topological Materials and Phenomena ; Molecular Junctions and Nanostructures
Authors: Zhaoxi Sun | Zhe Huai | Qiaole He | Zhirong Liu
Source:  (preprint, 2021-07-20)
Field: Chemistry — Spectroscopy

A General Picture of Cucurbit[8]uril Host-Guest Binding Describing, understanding, and designing complex interaction networks within macromolecular systems remain challenging in modern chemical research. Host-guest systems, despite their relative simplicity in both the structural feature and interaction patterns, still pose problems in theoretical modelling. The barrel-shaped supra-molecular container Cucurbit[8]uril (CB8) shows promising functionalities in various areas, e.g., catalysis and molecular recognition. It can stably coordinate a series of structurally diverse guests with high affinities. In this work, we examine the binding of 7 commonly abused drugs to the CB8 host, aiming at providing a general picture of CB8-guest binding. A thorough comparison of widely used fixed-charge models for drug-like molecules is presented. Extensive sampling of the configurational space of these host-guest systems is performed, and the binding pathway and interaction patterns of CB8-guest complexes are investigated in detail. Iterative refitting of the atomic charges suggests significant conformation-dependence of charge generation. The initial model generated at the original conformation could be inaccurate for new conformations explored during conformational search. Our investigations of the configurational space of CB8-drug complexes suggest that the host-guest interactions are more complex than expected. Despite the structural simplicities of these molecules, the conformational fluctuations of the host and the guest molecules and orientations of functional groups lead to the existence of an ensemble of binding modes (e.g., bracelet-like guest conformations and crescent free energy landscapes). Thus, understandings obtained from static calculations based on a single or several structures are limited for these host-guest interactions. The investigation protocol provides useful guidelines for studying host-guest binding, and the insights of the binding thermodynamics, performance of fixed-charge models, and binding patterns of the CB8-guest systems are useful for elucidating the binding mechanism of other host-guest complexes. Molecule ; Binding affinities ; Chemistry ; Chemical physics Advanced NMR Techniques and Applications ; Crystallography and molecular interactions ; Supramolecular Chemistry and Complexes
Authors: Eva‐Maria H. J. Esslinger | Jonas F. Schlagintweit | Greta G. Zámbó | Alexander M. Imhof | Robert M. Reich | Fritz E. Kühn
Source: Asian Journal of Organic Chemistry (article, 2021-08-16)
Field: Chemistry — Inorganic Chemistry

The Effect of <i>trans</i> Axial Isocyanide Ligands on Iron(II) Tetra‐NHC Complexes and their Reactivity in Olefin Epoxidation Abstract The performance of trans axially substituted mono‐( 2 a ) and bis( tert ‐butylisocyanide) ( 2 b ) complexes derived from the highly active bio‐inspired iron(II) (pre‐ )catalyst 2 containing an equatorial macrocyclic tetra N ‐heterocyclic carbene in homogenous olefin epoxidation catalysis is reported. H 2 O 2 is used as oxidant in combination with the Lewis acid Sc(OTf) 3 as additive resulting in a considerable improvement of catalytic activity. In contrast to other iron epoxidation catalysts, the introduction of π‐accepting isocyanide ligands does not improve the catalytic performance of 2 a and 2 b posed by cyclic voltammetry. However, besides their lower activity, a high temperature tolerance of both compounds is found as a unique feature for iron NHC epoxidation catalysts. Chemistry ; Catalysis ; Olefin fiber ; Carbene ; Tetra ; Isocyanide ; Reactivity (psychology) ; Lewis acids and bases ; Medicinal chemistry ; Cyclic voltammetry ; Combinatorial chemistry ; Stereochemistry ; Polymer chemistry ; Organic chemistry ; Electrochemistry Metal-Catalyzed Oxygenation Mechanisms ; Polyoxometalates: Synthesis and Applications ; Synthetic Organic Chemistry Methods
Authors: Daniela Pietrogiacomi | Maria Cristina Campa | Ida Pettiti | Simonetta Tuti | Giulia Luccisano | Leandro Ardemani | Igor Luisetto | Delia Gazzoli
Source: Materials (article, 2021-05-12)
Field: Materials Science — Materials Chemistry

Oscillatory Behaviour of Ni Supported on ZrO2 in the Catalytic Partial Oxidation of Methane as Determined by Activation Procedure Ni/ZrO<sub>2</sub> catalysts, active and selective for the catalytic partial oxidation of methane to syngas (CH<sub>4</sub>-CPO), were prepared by the dry impregnation of zirconium oxyhydroxide (Z<sub>hy</sub>) or monoclinic ZrO<sub>2</sub> (Z<sub>m</sub>), calcination at 1173 K and activation by different procedures: oxidation-reduction (<i>ox-red</i>) or direct reduction (<i>red</i>). The characterization included XRD, FESEM, in situ FTIR and Raman spectroscopies, TPR, and specific surface area measurements. Catalytic activity experiments were carried out in a flow apparatus with a mixture of CH<sub>4</sub>:O<sub>2</sub> = 2:1 in a short contact time. Compared to Z<sub>m</sub>, Z<sub>hy</sub> favoured the formation of smaller NiO particles, implying a higher number of Ni sites strongly interacting with the support. In all the activated Ni/ZrO<sub>2</sub> catalysts, the Ni-ZrO<sub>2</sub> interaction was strong enough to limit Ni aggregation during the catalytic runs. The catalytic activity depended on the activation procedures; the <i>ox-red</i> treatment yielded very active and stable catalysts, whereas the <i>red</i> treatment yielded catalysts with oscillating activity, ascribed to the formation of Ni<sup>δ+</sup> carbide-like species. The results suggested that Ni dispersion was not the main factor affecting the activity, and that active sites for CH<sub>4</sub>-CPO could be Ni species at the boundary of the metal particles in a specific configuration and nuclearity. Catalysis ; Calcination ; Partial oxidation ; Dispersion (optics) ; Syngas ; Non-blocking I/O ; Zirconium ; Inorganic chemistry ; Methane ; Nickel ; Chemistry ; Materials science ; Chemical engineering ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Catalysts for Methane Reforming
Authors: Yumna Zaheer | Thomas Vorup‐Jensen | Thomas J. Webster | Mukhtiar Ahmed | Waheed S. Khan | Ayesha Ihsan
Source: Nano Select (article, 2021-08-18)
Field: Materials Science — Biomaterials

Protein based nanomedicine: Promising therapeutic modalities against inflammatory disorders Abstract The safe and targeted delivery of pharmaceutical formulations has relied extensively on synthetic chemistry and other physicochemical approaches. The research paradigm is now especially changing towards green (or environmentally friendly) approaches, and several biopolymer‐based nanocarriers are marked as emerging nanomedicine tools. These have been developed to overcome problems with conventional drug carriers, which induce severe side effects, especially due to non‐specificity with detrimental effects on non‐targeted normal healthy cells. In addition, the phagocytosis of classic nanoparticles (NPs) and their degradation associated with the formation of oxygen radicals by the immune system are significant barriers for drug delivery. In this regard, protein nanocarriers appear as a promising approach to escape unwanted immune reactions. Moreover, these protein‐based NPs are generally non‐toxic, biodegradable, and even cost‐effective. As a less appreciated advantage, the surface properties of proteins are easily modified. There are, however, several challenges and limiting choices to make when choosing the type of modification to enable effective drug delivery. Here, we shed light on the role of protein nanocarriers for enhancing the bioavailability of different anti‐inflammatory drugs, including better macrophage targeting and overcoming biological barriers. This insight helps one to understand their broad utility in the treatment of inflammatory diseases and bridges the gap between naturaltherapeutic products and nanotechnology‐based delivery approaches, creating perhaps an optimal blend to meet some of our most persistent healthcare problems. Nanomedicine ; Therapeutic modalities ; Modalities ; Medicine ; Treatment modality ; Nanotechnology ; Internal medicine ; Materials science ; Nanoparticle Nanoparticle-Based Drug Delivery ; Advanced Drug Delivery Systems ; RNA Interference and Gene Delivery
Authors: Musa Erdoğan | Ali Yeşildağ | Barış Yıldız | Burak Tüzün | Özkan Özden
Source: Research Square (preprint, 2021-05-20)
Field: Chemistry — Organic Chemistry

Synthesis and Characterization of Some Benzidine-Based Azomethine Derivatives with Molecular Docking Studies and Anticancer Activities Benzidine ; Docking (animal) ; Chemistry ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Medicine Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Enzyme function and inhibition
Authors: Pachaiyappan Rajamalli | Federica Rizzi | Wenbo Li | Michael A. Jinks | Abhishek Kumar Gupta | Beth A. Laidlaw | Ifor D. W. Samuel | Thomas J. Penfold | Stephen M. Goldup | Eli Zysman‐Colman
Source: Angewandte Chemie (article, 2021-03-05)
Field: Materials Science — Materials Chemistry

Using the Mechanical Bond to Tune the Performance of a Thermally Activated Delayed Fluorescence Emitter** Abstract We report the characterization of rotaxanes based on a carbazole‐benzophenone thermally activated delayed fluorescence luminophore. We find that the mechanical bond leads to an improvement in key photophysical properties of the emitter, notably an increase in photoluminescence quantum yield and a decrease in the energy difference between singlet and triplet states, as well as fine tuning of the emission wavelength, a feat that is difficult to achieve when using covalently bound substituents. Computational simulations, supported by X‐ray crystallography, suggest that this tuning of properties occurs due to weak interactions between the axle and the macrocycle that are enforced by the mechanical bond. This work highlights the benefits of using the mechanical bond to refine existing luminophores, providing a new avenue for emitter optimization that can ultimately increase the performance of these molecules. Carbazole ; Benzophenone ; Covalent bond ; Common emitter ; Fluorescence ; Quantum yield ; Photoluminescence ; Materials science ; Photochemistry ; Luminophore ; Bond energy ; Molecule ; Singlet state ; Nanotechnology ; Chemistry ; Optoelectronics ; Luminescence ; Excited state ; Optics ; Atomic physics ; Organic chemistry ; Physics Luminescence and Fluorescent Materials ; Supramolecular Chemistry and Complexes ; Molecular Junctions and Nanostructures
Authors: Daniel A. Campos | Sophia Blanché | Hermann F. Jungkunst | Allan Philippe
Source: Environmental Science and Pollution Research (article, 2021-05-22)
Field: Chemistry — Inorganic Chemistry

Distribution, behavior, and erosion of uranium in vineyard soils Phosphate fertilization contributes to an input of uranium (U) in agricultural soils. Although its accumulation and fate in agricultural soils have been previously studied, its colloidal transport and accumulation along slopes through erosion have been studied to a lesser extent in viticulture soils. To bridge this gap, the contents and potential mobility of U were investigated in vineyard model soils in the Rhineland-Palatinate region, Germany. In addition to elevated U contents, U was expected to associate with colloids and subject to erosion, thus accumulating on slope foots and in soils with fine structure, and reflecting a greater variability. Moreover, another expectation was the favorable erosion/mobility of U in areas with greater carbonate content. This was tested in three regional locations, at different slope positions and through soil horizon depths, with a total of 57 soil samples. The results show that U concentrations (0.48-1.26 ppm) were slightly higher than proximal non-agricultural soils (0.50 ppm), quite homogenous along slope positions, and slightly higher in topsoils. Assuming a homogeneous fertilization, the vertical translocation of U in soil was most probably higher than along the slope by erosion. In addition, carbonate content and soil texture correlated with U concentrations, whereas other parameters such as organic carbon and iron contents did not. The central role of carbonate and soil texture for the prediction of U content was confirmed using decision trees and elastic net, although their limited prediction power suggests that a larger sample size with a larger range of U content is required to improve the accuracy. Overall, we did not observe neither U nor colloids accumulating on slope foots, thus suggesting that soils are aggregate-stable. Lastly, we suggested considering further soil parameters (e.g., Ca<sup>2+</sup>, phosphorus, alkali metals) in future works to improve our modelling approach. Overall, our results suggest U is fortunately immobile in the studied locations. Soil water ; Vineyard ; Soil science ; Environmental science ; Erosion ; Subsoil ; Carbonate ; Soil texture ; Environmental chemistry ; Geology ; Hydrology (agriculture) ; Chemistry ; Geomorphology ; Geography Radioactive element chemistry and processing ; Radioactive contamination and transfer ; Radioactivity and Radon Measurements
Authors: Yu Gan | Jian Zhou | Zhimei Sun
Source: Journal of Materials Informatics (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

Prediction of the atomic structure and thermoelectric performance for semiconducting Ge1Sb6Te10 from DFT calculations Journal of Materials Informatics (JMI) is an international peer-reviewed, open access journal. The journal provides a platform for presentation, publication, and exchange of materials informatics research, seeking to break down barriers among materials science and engineering, data science and engineering, and artificial intelligence. The journal also provides a venue for presenting innovative approaches to overcome the difficulties in unraveling the complexity of data associated with numerous factors including noise, uncertainty, and small amount, to achieve the quantum jump from data to knowledge. Materials informatics ; Informatics ; Computer science ; Data science ; Presentation (obstetrics) ; Data exchange ; Health informatics ; Engineering informatics ; Engineering ; World Wide Web ; Political science ; Electrical engineering Advanced Thermoelectric Materials and Devices ; Machine Learning in Materials Science ; Chalcogenide Semiconductor Thin Films
Authors: Jie Gao | Wenda Zhang | Linlin Wang | Yu‐Xuan Chen | Ya‐Xiang Shi | Wei Ji | Zexiao Xu | Xiaodong Yan | Zhi‐Guo Gu
Source: Macromolecular Materials and Engineering (article, 2021-11-19)
Field: Materials Science — Materials Chemistry

Ultrafast Photochromic Self‐Healing Polymer Gels with Tunable Fluorescence Abstract Photoresponsive self‐healing polymer gels have great potential in the fields of optical information storage, artificial intelligence, and wearable flexible devices. Herein, a series of photoresponsive self‐healing gels based on dynamic imine bonds are synthesized in which the photoresponsive functions are achieved by the incorporation of the chromophore 1,2‐bis(5′‐formyl‐2′‐methylthien‐3′‐yl)perfluorocyclopentene (DEA) and the fluorophore 2,5‐dimethoxybenzene‐1,4‐diformaldehyde derivatives (DBD) through the Schiff base reactions between DEA/DBD and aminopropylmethylsiloxane‐dimethylsiloxane copolymers. The gels show ultrafast photoresponsive ability with the transition from yellow to blue within 10 s under 254 nm UV–Vis and subsequent color restoration within 20 s under visible light, derived from the fast ring‐closure and ‐opening transition of DEA. Interestingly, the molecular states of DEA have influence on the on–off intensity of the fluorescence. The gels with ring‐opened DEA show stronger blue fluorescence than the ones with ring‐closed DEA. In addition, the cross‐linked dynamic imine bond enables the gels to self‐heal quickly, and the wound disappears within 10 min without any external stimuli. Fluorophore ; Materials science ; Photochromism ; Fluorescence ; Chromophore ; Photochemistry ; Imine ; Polymer ; Diarylethene ; Self-healing ; Copolymer ; Polymer chemistry ; Nanotechnology ; Chemistry ; Organic chemistry ; Catalysis ; Optics ; Composite material Photochromic and Fluorescence Chemistry ; Polymer composites and self-healing ; Polydiacetylene-based materials and applications
Authors: Ashish Pandey | Ramakrishna Surya | Matthew R. Maschmann | Prasad Calyam
Source:  (article, 2021-10-12)
Field: Materials Science — Materials Chemistry

Reinforcement Learning based Carbon Nanotube Growth Automation Experimental research such as cell cultures and carbon nanotube (CNT) growth are largely governed by following predefined execution protocols with fine-tuned control of parameters. There are promising opportunities to apply reinforcement learning (RL), an established learning technique in the area of artificial intelligence, in order to automate CNT growth process and accelerate related scientific breakthroughs in material discovery. Although there are benefits in RL-based exploration and exploitation methodologies, there are also challenges in developing relevant learning policies in experimental settings relating to CNT growth. In this paper, we present a novel data-driven RL approach for assisting experimental CNT growth. Our approach focuses on developing an RL model to learn from simulation-based images and characteristics of temporal CNT growth, considering various growth parameters. Our RL model learns from CNT growth variation in a simulation-based environment where critical control parameters, such as density, growth rate, tube radius, tube stiffness, and Van der Waals forces, are used. Our RL model enables CNT growth automation in order to explore of a wider range of growth conditions, and improve reproducibility. The ultimate goal of our RL model is to achieve desired CNT growth by dynamically controlling growth parameters throughout a sequence of experiments. We evaluate the effectiveness of our RL approach by measuring the improvement in the maximum compressive strength of a carbon nanotube ‘with’ and ‘without’ the RL model. Our results show the effectiveness of course correction recommended by our RL approach when controlling the parameters of angular deviation and rate of growth of carbon nanotubes, when compared against non-regulated CNT growth. Reinforcement learning ; Carbon nanotube ; Automation ; Computer science ; Artificial intelligence ; Materials science ; Nanotechnology ; Simulation ; Mechanical engineering ; Engineering Carbon Nanotubes in Composites ; Force Microscopy Techniques and Applications ; Neuroscience and Neural Engineering