jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mohammad Azam | Manasa Manasa | T. Zajarniuk | R. Diduszko | Tomasz Cetner | A. Morawski | A. Wiśniewski | Shiv J. Singh
Source: arXiv (Cornell University) (preprint, 2023-11-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Antimony Doping Effect on the Superconducting Properties of SmFeAs(O,F) We report the synthesis and characterization of a series of antimony-doped SmFeAs1-xSbxO0.8F0.2 (x = 0, 0.01, 0.03, 0.05, 0.1, 0.2, and 0.3) bulks to investigate the twin doping effects on the superconducting properties of SmFeAs(O,F) caused by fluorine (F) incorporation at O-site in SmO layer and antimony (Sb) substitution at As-site in the conducting layer (FeAs). Since the antimony (Sb) has a larger size than arsenic (As), the enhancement of lattice parameters has been confirmed by the XRD analysis. Microstructural analysis confirms that Sb-doping leads to a small improvement in the sample density and an increase in the inhomogeneity of the constituent elements, especially at higher Sb-doping levels. The parent compound SmFeAsO0.8F0.2 has shown the superconducting transition (Tc) at ~54 K, which is systematically reduced with the antimony doping contents (x). Our investigation indicates that the Sb-doped SmFeAs(O,F) phase at low levels is less prone to the multiphase formation than at high levels, which affects the inter- and intragranular behaviour originating from the microstructure nature of 1111 bulks. The critical current density (Jc) of the parent compound has almost the same value as previously reported, which is suppressed slowly with increased Sb-doping. It could be due to the reduced grain connections and the effective pinning centers. This study confirms that the superconducting FeAs layer doping with larger ions at arsenic sites does not support the superconducting properties of Sm1111, which is a distinct behavior from that of Sb-doped CeFeAs(O,F) and LaFeAs(O,F). Antimony ; Doping ; Materials science ; Superconductivity ; Arsenic ; Microstructure ; Condensed matter physics ; Analytical Chemistry (journal) ; Ion ; Crystallography ; Metallurgy ; Chemistry ; Physics ; Optoelectronics Iron-based superconductors research
Authors: Amal A. El- Sawy | Eman Sarwat
Source: Baghdad Science Journal (article, 2023-07-20)
Field: Materials Science — Materials Chemistry

Comparative Study of Gamma- Ray Shielding Parameters for Different Epoxy Composites In the current work various types of epoxy composites were added to concrete to enhance its effectiveness as a gamma- ray shield. Four epoxy samples of (E/clay/B4C) S1, (E/Mag/B4C) S2, (EPIL) S3 and (Ep) S4 were used in a comparative study of gamma radiation attenuation properties of these shields that calculating using Mont Carlo code (MCNP-5). Adopting Win X-com software and Artificial Neural Network (ANN), µ/ρ revealed great compliance with MCNP-5. By applying (µ/ρ) output for gamma at different energies, HVL, TVL and MFP have been also estimated. ANN technique was simulated to estimate (µ/ρ) and dose rates. According to the results, µ/ρ of all epoxy samples scored higher than standard concrete. Both S2 and S3 samples having higher values of µ/ρ, show minimum dose rate values. (µ/ρ) and RPE% values were enhanced, the concrete containing E/Mag/B4C (S2) had the best results, while the concrete containing Ep (S4) provide the worst results. The ANN prediction results take 15 sec for estimating gamma doses corresponding to seventeen shield thicknesses, while the theoretical MCNP-5 results took approximately between 7 to 10 hours for five gamma doses. ANN provides excellent predictions with a high degree of correlation depending on increasing the number of attenuation parameters used in the training process. Also, it predicts gamma dose rates for a large number of shield thicknesses that cannot be calculated theoretically in a very short time. This supports, the created epoxy composite offers good attenuation properties for many shielding applications and could be proposed as an injecting mortar for cracks in biological shields and the walls of diagnostic and radiotherapy rooms. However, further investigations are planned for different filler ratios, for comparison purposes, in order to reach optimal shielding properties Epoxy ; Attenuation ; Electromagnetic shielding ; Materials science ; Composite material ; Shield ; Gamma ray ; Shields ; Nuclear physics ; Optics ; Physics Radiation Shielding Materials Analysis ; Graphite, nuclear technology, radiation studies ; Nuclear Physics and Applications
Authors: Radosław Gruska | Alina Kunicka‐Styczyńska | Andrzej Jaśkiewicz | Andrzej Baryga | Stanisław Brzeziński | Beata Świącik
Source: Molecules (article, 2023-07-20)
Field: Chemistry — Analytical Chemistry

Fourier Transform Mid-Infrared Spectroscopy (FT-MIR) as a Method of Identifying Contaminants in Sugar Beet Production Process—Case Studies Food safety has received considerable attention in recent years. Methods for rapid identification of a variety contaminants in both the final product and the manufacturing process are constantly developing. This study used Fourier Transform Mid-Infrared Spectroscopy (FT-MIR) spectroscopy to identify various contaminants endangering white sugar production. It was demonstrated that inorganic compounds (calcium carbonate—CaCO3), plastic contaminants (polypropylene), and oily contaminants (compressor sealing and lubrication lubricant) can be identified with a high degree of precision. FT-MIR spectroscopy was proved to be a useful technique for detecting sugar contaminants rapidly and precisely even without the application of a sophisticated spectra analysis. Commercial databases of reference spectra usage significantly simplify and facilitate the application of this method. Contamination ; Fourier transform infrared spectroscopy ; Infrared spectroscopy ; Process engineering ; Spectroscopy ; Sugar ; Sugar beet ; Materials science ; Environmental science ; Pulp and paper industry ; Chemistry ; Chemical engineering ; Organic chemistry ; Engineering ; Agronomy Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: Márton Gadanecz | Zsolt Fazekas | Gyula Pálfy | Dóra K. Menyhárd | András Perczel
Source: International Journal of Molecular Sciences (article, 2023-07-28)
Field: Materials Science — Materials Chemistry

NMR-Chemical-Shift-Driven Protocol Reveals the Cofactor-Bound, Complete Structure of Dynamic Intermediates of the Catalytic Cycle of Oncogenic KRAS G12C Protein and the Significance of the Mg2+ Ion In this work, catalytically significant states of the oncogenic G12C variant of KRAS, those of Mg<sup>2+</sup>-free and Mg<sup>2+</sup>-bound GDP-loaded forms, have been determined using CS-Rosetta software and NMR-data-driven molecular dynamics simulations. There are several Mg<sup>2+</sup>-bound G12C KRAS/GDP structures deposited in the Protein Data Bank (PDB), so this system was used as a reference, while the structure of the Mg<sup>2+</sup>-free but GDP-bound state of the RAS cycle has not been determined previously. Due to the high flexibility of the Switch-I and Switch-II regions, which also happen to be the catalytically most significant segments, only chemical shift information could be collected for the most important regions of both systems. CS-Rosetta was used to derive an "NMR ensemble" based on the measured chemical shifts, which, however, did not contain the nonprotein components of the complex. We developed a torsional restraint set for backbone torsions based on the CS-Rosetta ensembles for MD simulations, overriding the force-field-based parametrization in the presence of the reinserted cofactors. This protocol (csdMD) resulted in complete models for both systems that also retained the structural features and heterogeneity defined by the measured chemical shifts and allowed a detailed comparison of the Mg<sup>2+</sup>-bound and Mg<sup>2+</sup>-free states of G12C KRAS/GDP. Catalytic cycle ; Cofactor ; Chemistry ; KRAS ; Catalysis ; Ion ; Biophysics ; Cell biology ; Biochemistry ; Mutation ; Biology ; Enzyme ; Organic chemistry Enzyme Structure and Function ; Protein Structure and Dynamics ; Microtubule and mitosis dynamics
Authors: Ivana Marin | Sven Gotovac | Vladan Papić
Source: Advances in Science Technology and Engineering Systems Journal (article, 2023-03-01)
Field: Chemistry — Analytical Chemistry

Development and Analysis of Models for Detection of Olive Trees In this paper, an automatic method for detection of olive trees in RGB images acquired by an unmanned aerial vehicle (UAV) is developed. Presented approach is based on the implementation of RetinaNet model and DeepForest Phyton package. Due to fact that original (pretrained) model used in DeepForest package has been built on images of various types of trees but without images of olive trees, original model detection was unsatisfactory. Therefore, a new image dataset of olive trees was created using sets of images chosen from five olive groves. For neural network training, individual olive trees were manually labeled, and new models were generated. Each model has been trained on different set of images from selected olive groves. Pretrained model and new models were compared and evaluated for various test scenarios. Obtained results showed high precision and recall values of proposed approach and great improvement in performance compared to the pretrained model. Olive trees ; Biology ; Botany Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Remote Sensing in Agriculture
Authors: Yusuke Kanematsu | Hiroko Kondo | Yu Takano
Source: International Journal of Molecular Sciences (article, 2023-12-06)
Field: Chemistry — Spectroscopy

Computational Exploration of Minimum Energy Reaction Pathway of N2O Formation from Intermediate I of P450nor Using an Active Center Model P450nor is a heme-containing enzyme that catalyzes the conversion of nitric oxide (NO) to nitrous oxide (N<sub>2</sub>O). Its catalytic mechanism has attracted attention in chemistry, biology, and environmental engineering. The catalytic cycle of P450nor is proposed to consist of three major steps. The reaction mechanism for the last step, N<sub>2</sub>O generation, remains unknown. In this study, the reaction pathway of the N<sub>2</sub>O generation from the intermediate <i>I</i> was explored with the B3LYP calculations using an active center model after the examination of the validity of the model. In the validation, we compared the heme distortions between P450nor and other oxidoreductases, suggesting a small effect of protein environment on the N<sub>2</sub>O generation reaction in P450nor. We then evaluated the electrostatic environment effect of P450nor on the hydride affinity to the active site with quantum mechanics/molecular mechanics (QM/MM) calculations, confirming that the affinity was unchanged with or without the protein environment. The active center model for P450nor showed that the N<sub>2</sub>O generation process in the enzymatic reaction undergoes a reasonable barrier height without protein environment. Consequently, our findings strongly suggest that the N<sub>2</sub>O generation reaction from the intermediate <i>I</i> depends sorely on the intrinsic reactivity of the heme cofactor bound on cysteine residue. Chemistry ; Active site ; Catalysis ; Catalytic cycle ; Hydride ; Heme ; Nitric oxide ; Cofactor ; Active center ; Combinatorial chemistry ; Enzyme ; Biochemistry ; Organic chemistry Mass Spectrometry Techniques and Applications ; Pharmacogenetics and Drug Metabolism ; Hemoglobin structure and function
Authors: Pulat Saidakhmetov | Irina Piyanzina | Amina Faskhutdinova | Oleg V. Nedopekin | G.M. Adyrbekova | Gulzagira Baiman | Zhamilya Suyerkulova | I. V. Romanova
Source: Crystals (article, 2023-10-12)
Field: Chemistry — Inorganic Chemistry

Ab Initio Magnetic Properties Simulation of Nanoparticles Based on Rare Earth Trifluorides REF3 (RE = Tb, Dy, Ho) Recently, nanoparticles based on rare earth fluorides have been widely investigated due to their possible medical and spintronic applications, where it is desirable to know the magnetic moment volume distribution. However, this feature is hard to find out from the experiments, so we employ ab initio spin-polarized calculations for this purpose in order to find out the tendencies and common features in three different compounds. In the present work, the nanoparticles of dipole magnets with different sizes, namely TbF3, DyF3 and HoF3, were simulated, and optimized structures were found. We present the optimized structures for the particles with various sizes, as well as for slabs constructed from same compounds. Lastly, for optimized geometries, the analysis of magnetic moments’ distribution over the nanoparticles and slabs volume was performed. Nanoparticle ; Spintronics ; Materials science ; Dipole ; Ab initio ; Magnetic moment ; Rare earth ; Ab initio quantum chemistry methods ; Magnet ; Magnetic nanoparticles ; Spin (aerodynamics) ; Condensed matter physics ; Work (physics) ; Moment (physics) ; Nanotechnology ; Ferromagnetism ; Chemistry ; Thermodynamics ; Physics ; Molecule ; Classical mechanics ; Metallurgy Inorganic Fluorides and Related Compounds ; Magnetism in coordination complexes ; Inorganic Chemistry and Materials
Authors: Hongjiang Li | Long Zhao | Hongxiang Zong | Xiangdong Ding | Turab Lookman | Jun Sun | Graeme J. Ackland
Source: Physical review. B./Physical review. B (article, 2023-05-30)
Field: Materials Science — Materials Chemistry

Enhancing the stability of the <i>ω</i> phase of zirconium alloys via local interlayer twists The addition of solute provides an effective means to alter the stability of phases in metallic materials. This is particularly true for the metastable t\ensuremath{\omega} phase in Ti- and Zr-based alloys; however, the underlying mechanism remains inconclusive. In the present work, we show that the $\ensuremath{\omega}\ensuremath{\rightarrow}\ensuremath{\beta}$ phase-transformation process can be hindered to stabilize the \ensuremath{\omega} phase over a wide temperature and pressure range. This is demonstrated by molecular dynamics simulations of Zr-Nb alloys. In particular, we show that Nb dopants lead to the formation of a defect structure in the Zr-\ensuremath{\omega} phase, i.e., there is a corotation of six atoms in the {0002} plane by 30 \ifmmode^\circ\else\textdegree\fi{} along the $c$ axis of the \ensuremath{\omega} lattice. We refer to this as a local interlayer twist (LIT). The LITs are energetically preferred within Nb-rich regions and can interlock \ensuremath{\omega} lattices, thus retarding the $\ensuremath{\omega}\ensuremath{\rightarrow}\ensuremath{\beta}$ phase transformation. Furthermore, our density-functional theory calculations suggest that this mechanism should work in Zr- and Ti-based alloys with small solute atoms. The findings enrich our understanding of complex phase-transformation kinetics in alloys. Omega ; Metastability ; Materials science ; Zirconium ; Phase (matter) ; Lattice (music) ; Metal ; Condensed matter physics ; Crystallography ; Physics ; Thermodynamics ; Quantum mechanics ; Chemistry ; Metallurgy Nuclear Materials and Properties ; Titanium Alloys Microstructure and Properties ; Intermetallics and Advanced Alloy Properties
Authors: Lydia Boualem | Zeynep Serinyel | André Nicolle | Maxence Lailliau | Philippe Dagaut | Guillaume Dayma
Source: Fuel (article, 2023-07-14)
Field: Materials Science — Materials Chemistry

Experimental and modeling study of the oxidation of fenchone, a high-energy density fuel-additive Chemistry ; Methacrolein ; Formaldehyde ; Toluene ; Mole fraction ; Benzene ; Acetaldehyde ; Analytical Chemistry (journal) ; Organic chemistry ; Physical chemistry ; Ethanol ; Polymerization Catalytic Processes in Materials Science ; Advanced Combustion Engine Technologies ; Catalysis and Oxidation Reactions
Authors: Patrizio Graziosi | Neophytos Neophytou
Source: ACS Applied Electronic Materials (article, 2023-11-01)
Field: Materials Science — Materials Chemistry

The Role of Electronic Bandstructure Shape in Improving the Thermoelectric Power Factor of Complex Materials The large variety of complex electronic structure materials and their alloys offer highly promising directions for improvements in thermoelectric (TE) power factors (PFs). Their electronic structure contains rich features, referred to as “surface complexity”, such as highly anisotropic, warped energy surface shapes with elongated features and threads in some cases. In this work, we use Boltzmann transport simulations to quantify the influence that the shape of the electronic structure energy surfaces has on the PF. Using analytical ellipsoidal bands, as well as realistic bands from a group of half-Heuslers, we show that band shape complexity alone can offer an advantage to the PF by ∼3× in realistic cases. However, the presence of anisotropic scattering mechanisms, such as ionized impurity or polar optical phonon scattering, can reduce these improvements by up to ∼50%. We show that expressions based on the simple ratio of the density of states effective mass to the conductivity effective mass, mDOS/mC, together with the number of valleys, can capture the anisotropy shape with a moderate to high degree of correlation. For this, we use a convenient way to extract these masses by mapping the complex bandstructures of materials to parabolic electronic structures, which can be done without the need for Boltzmann transport codes. Despite the fact that the PF depends on many parameters, information about the benefits of the band shape alone, may be very useful for identifying and understanding the performance of novel thermoelectric materials. Anisotropy ; Effective mass (spring–mass system) ; Thermoelectric effect ; Electronic band structure ; Scattering ; Boltzmann constant ; Computational physics ; Electronic structure ; Condensed matter physics ; Seebeck coefficient ; Phonon ; Materials science ; Work (physics) ; Boltzmann equation ; Thermoelectric materials ; Statistical physics ; Physics ; Optics ; Classical mechanics ; Quantum mechanics Advanced Thermoelectric Materials and Devices ; 2D Materials and Applications ; Heusler alloys: electronic and magnetic properties
Authors: Jordi Ballesteros–Soberanas | Marta Mon | Antonio Leyva‐Pérez
Source: Organic & Biomolecular Chemistry (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

Diastereoisomeric enrichment of 1,4-enediols and H<sub>2</sub>-splitting inhibition on Pd-supported catalysts Pd-supported catalysts are fundamental tools in organic reactions involving H<sub>2</sub> splitting. Here we show that 1,4-enediols enriched in one diastereoisomer are produced from the classical Pd-catalyzed semi-hydrogenation reaction with H<sub>2</sub>, starting from the corresponding, widely available 1,4-diacetylenic diols. The semi-hydrogenation reaction proceeds concomitantly with the desymmetrization of the <i>meso</i>/racemic form of the enediol. We also show that these products, if added in advance to H<sub>2</sub>, completely inactivate the Pd catalyst (only when added before H<sub>2</sub>). These results provide a simple way not only to produce 1,4-enediols enriched in one diastereoisomer by a classical catalytic method but also to stop H<sub>2</sub> dissociation on Pd nanoparticles. Chemistry ; Diastereomer ; Catalysis ; Desymmetrization ; Dissociation (chemistry) ; Reaction conditions ; Medicinal chemistry ; Combinatorial chemistry ; Palladium ; Organic chemistry ; Enantioselective synthesis Asymmetric Hydrogenation and Catalysis ; Carbon dioxide utilization in catalysis
Authors: Paulina Ballesta | Carlos Maldonado | Freddy Mora | Daniel Mieres‐Castro | Alejandro del Pozo | Gustavo A. Lobos
Source: Plants (article, 2023-01-18)
Field: Chemistry — Analytical Chemistry

Spectral-Based Classification of Genetically Differentiated Groups in Spring Wheat Grown under Contrasting Environments The global concern about the gap between food production and consumption has intensified the research on the genetics, ecophysiology, and breeding of cereal crops. In this sense, several genetic studies have been conducted to assess the effectiveness and sustainability of collections of germplasm accessions of major crops. In this study, a spectral-based classification approach for the assignment of wheat cultivars to genetically differentiated subpopulations (genetic structure) was carried out using a panel of 316 spring bread cultivars grown in two environments with different water regimes (rainfed and fully irrigated). For that, different machine-learning models were trained with foliar spectral and genetic information to assign the wheat cultivars to subpopulations. The results revealed that, in general, the hyperparameters ReLU (as the activation function), adam (as the optimizer), and a size batch of 10 give neural network models better accuracy. Genetically differentiated groups showed smaller differences in mean wavelengths under rainfed than under full irrigation, which coincided with a reduction in clustering accuracy in neural network models. The comparison of models indicated that the Convolutional Neural Network (CNN) was significantly more accurate in classifying individuals into their respective subpopulations, with 92 and 93% of correct individual assignments in water-limited and fully irrigated environments, respectively, whereas 92% (full irrigation) and 78% (rainfed) of cultivars were correctly assigned to their respective classes by the multilayer perceptron method and partial least squares discriminant analysis, respectively. Notably, CNN did not show significant differences between both environments, which indicates stability in the prediction independent of the different water regimes. It is concluded that foliar spectral variation can be used to accurately infer the belonging of a cultivar to its respective genetically differentiated group, even considering radically different environments, which is highly desirable in the context of crop genetic resources management. Germplasm ; Cultivar ; Convolutional neural network ; Biology ; Artificial intelligence ; Linear discriminant analysis ; Multilayer perceptron ; Irrigation ; Artificial neural network ; Mathematics ; Agronomy ; Biotechnology ; Pattern recognition (psychology) ; Machine learning ; Computer science Spectroscopy and Chemometric Analyses ; Leaf Properties and Growth Measurement ; Wheat and Barley Genetics and Pathology
Authors: Yu-Ya Huang | Zui-Harng Lee | Kai‐Chi Chang | Zhiyuan Wu | Cheng-Chang Lee | Min-Hsuan Tsou | Hsiu-Mei Lin
Source: RSC Advances (article, 2023-01-01)
Field: Materials Science — Biomaterials

Mesoporous silica nanoparticles with dual-targeting agricultural sources for enhanced cancer treatment <i>via</i> tritherapy In this study, we introduced dual-targeting folic acid (FA) and hyaluronic acid (HA) modified on the surface of rice husk mesoporous silica nanoparticles (rMSNs). The rMSNs were employed as a drug delivery system loaded with camptothecin (CPT) as a model drug, Eu<sup>3+</sup> ions as a photosensitizer for photodynamic therapy (PDT), bismuth (Bi) for photothermal therapy (PTT), and Gd<sup>3+</sup> ions for magnetic resonance imaging (MRI) to develop novel nanoparticles, rMSN-EuGd-Bi@CPT-HA-FA, with dual-targeted function and triple therapy for cancer treatment. The results of the cell cytotoxicity experiment showed that the A549 cancer cells had a survival rate of approximately 35% when treated with 200 μg mL<sup>-1</sup> of rMSN-EuGd-Bi@CPT-HA-FA under 808 nm irradiation for 15 min. The dual-targeted function and synergistic treatment of CPT, PTT, and PDT were also responsible for the 20% survival rate of the A549 cancer cells treated with 200 μg mL<sup>-1</sup> of rMSN-EuGd-Bi@CPT-HA-FA under 808 nm irradiation for 30 min. The results showed that rMSN-EuGd-Bi@CPT-HA-FA can effectively combine chemotherapy (through CPT), PDT, and PTT for cancer treatment. Mesoporous silica ; Dual (grammatical number) ; Nanoparticle ; Mesoporous material ; Nanotechnology ; Cancer ; Chemistry ; Materials science ; Medicine ; Internal medicine ; Organic chemistry ; Catalysis Nanoparticle-Based Drug Delivery ; Graphene and Nanomaterials Applications ; Nanoplatforms for cancer theranostics