jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Matthew P. Kroonblawd | Amitesh Maiti | Brandon Zimmerman | Brad A. Steele | Joel G. Christenson | Ryan Austin | Laurence E. Fried
Source: ChemRxiv (preprint, 2024-04-21)
Field: Materials Science — Materials Chemistry

Self-Similarity in the Formation of Explosive Hot Spots High explosive detonation starts with formation of hot spots at microstructural defects but has eluded "full physics" atomistic modeling treatment at micron length scales. To this end, we develop an image distinguishability analysis to summarize multimicron all-atom MD simulations of hot spot formation for pore sizes between 10 and 300 nm to show that all but the smallest hot spots exhibit self-similar size scaling. Through grain-scale modeling we link this behavior to the material’s rate-insensitive mechanical strength. Our results bolster confidence in insights from small-scale MD simulations and provide means to quantitatively compare complex processes at diverse length scales. Explosive material ; Similarity (geometry) ; Hot spot (computer programming) ; Spots ; Materials science ; Chemistry ; Computer science ; Artificial intelligence ; Image (mathematics) High-Velocity Impact and Material Behavior ; Energetic Materials and Combustion
Authors: Chou‐Yuan Lee | Sheng Wang | Jian-Qiong Huang
Source: Scientific Reports (article, 2024-12-27)
Field: Chemistry — Analytical Chemistry

Clustering and classification for dry bean feature imbalanced data The traditional machine learning methods such as decision tree (DT), random forest (RF), and support vector machine (SVM) have low classification performance. This paper proposes an algorithm for the dry bean dataset and obesity levels dataset that can balance the minority class and the majority class and has a clustering function to improve the traditional machine learning classification accuracy and various performance indicators such as precision, recall, f1-score, and area under curve (AUC) for imbalanced data. The key idea is to use the advantages of borderline-synthetic minority oversampling technique (BLSMOTE) to generate new samples using samples on the boundary of minority class samples to reduce the impact of noise on model building, and the advantages of K-means clustering to divide data into different groups according to similarities or common features. The results show that the proposed algorithm BLSMOTE + K-means + SVM is superior to other traditional machine learning methods in classification and various performance indicators. The BLSMOTE + K-means + DT generates decision rules for the dry bean dataset and the the obesity levels dataset, and the BLSMOTE + K-means + RF ranks the importance of explanatory variables. These experimental results can provide scientific evidence for decision-makers. Oversampling ; Support vector machine ; Cluster analysis ; Artificial intelligence ; Machine learning ; Computer science ; Decision tree ; Random forest ; Decision boundary ; Class (philosophy) ; Feature (linguistics) ; Data mining ; k-means clustering ; Pattern recognition (psychology) Spectroscopy and Chemometric Analyses ; Imbalanced Data Classification Techniques ; Food Supply Chain Traceability
Authors: Yuk‐Wah Tsang | Hsiao-Ju Fu | Pei‐Chen Huang | B.N. Yadav | De‐Shin Liu
Source: Journal of Mechanics (article, 2024-01-01)
Field: Materials Science — Polymers and Plastics

Injection moulding process parameter and strain rate dependence mechanical properties measurement and theoretical estimation of EVA polymer foam Abstract In this study, the combined experimental and theoretical estimation on elastic characteristics of EVA (ethylene-vinyl acetate) copolymer material is demonstrated. Strain rate dependence stress–strain behavior of EVA in raw and foam material form are measured by the quasi static and dynamic compression test. Simultaneously, the influence of different mould temperature and injection pressure on mechanical properties of EVA foam are investigated. According to the usage scenario of EVA foam in sport footwear application, the EVA foam is generally deformed under higher strain rate as compared with the quasi-static compression condition. For this reason, the stress–strain behavior of EVA foam under high strain rates of 2.66 × 10−3 and 2.66 × 10−2 s−1 are estimated. The analytic results revealed that the strain rate slightly enhanced the modulus of EVA foam, and the foregoing strain rate effect is substituting into the classic Young's modulus estimation equation of closed cell cellular solid. Accordingly, the strain rate dependence Young's modulus of EVA foam is successfully estimated by both experiment and theoretical estimation. Materials science ; Composite material ; Modulus ; Strain rate ; Ethylene-vinyl acetate ; Strain (injury) ; Stress (linguistics) ; Compression (physics) ; Polymer ; Elastic modulus ; Copolymer Polymer Foaming and Composites ; Cellular and Composite Structures ; Injection Molding Process and Properties
Authors: Alexandre Almeida | David L. Turner | Marta A. Silva | Carlos A. Salgueiro
Source: Journal of Biological Chemistry (article, 2024-12-14)
Field: Chemistry — Inorganic Chemistry

New insights in uranium bioremediation by cytochromes of the bacterium Geotalea uraniireducens The bacterium Geotalea uraniireducens, commonly found in uranium-contaminated environments, plays a key role in bioremediation strategies by converting the soluble hexavalent form of uranium (U(VI)) into less soluble forms (e.g., U(IV)). While most of the reduction and concomitant precipitation of uranium occur outside the cells, there have been reports of important reduction processes taking place in the periplasm. In any case, the triheme periplasmic cytochromes are key players, either by ensuring an effective interface between the cell's interior and exterior or by directly participating in the reduction of the metal. Therefore, understanding the functional mechanism of the highly abundant triheme cytochromes in G. uraniireducens' is crucial for elucidating the respiratory pathways in this bacterium. In this work, a detailed functional characterization of the triheme cytochromes PpcA and PpcB from G. uraniireducens was conducted using NMR and visible spectroscopy techniques. Despite sharing high amino acid sequence identity and structural homology with their counterparts from Geobacter sulfurreducens, the results showed that the heme reduction potential values are less negative, the order of oxidation of the hemes is distinct, and the redox and redox-Bohr network of interactions revealed unprecedented functional mechanisms in the cytochromes of G. uraniireducens. In these cytochromes, the reduction potential values of the three heme groups are much more similar, resulting in a narrower range of values, that facilitates directional electron flow from the inner membrane, thereby optimizing the uranium reduction. Bioremediation ; Uranium ; Bacteria ; Chemistry ; Environmental chemistry ; Microbiology ; Biology ; Metallurgy ; Materials science ; Genetics Radioactive element chemistry and processing ; Radioactive contamination and transfer ; Geochemistry and Elemental Analysis
Authors: Daniel Félix-González | Pablo del Mazo‐Sevillano | Alfredo Aguado | Octavio Roncero | J. Le Bourlot | E. Roueff | Franck Le Petit | Émeric Bron
Source: Astronomy and Astrophysics (article, 2024-12-19)
Field: Chemistry — Spectroscopy

Inelastic H + H<sub>3</sub><sup>+</sup> collision rates and their impact on the determination of the excitation temperature of H<sub>3</sub><sup>+</sup> Context. In diffuse interstellar clouds, the excitation temperature derived from the lowest levels of H 3 + is systematically lower than that derived from H 2 . The differences may be attributed to the lack of state-specific formation and destruction rates of H 3 + , which are needed to thermalize the two species. Aims. In this work, we aim to investigate the possible influence of rotational excitation collisions of H 3 + with atomic hydrogen on its excitation temperature. Methods. We used a time-independent close-coupling method to calculate the state-to-state rate coefficients, incorporating a very accurate and full-dimensional potential energy surface recently developed for H 4 + . We take a symmetric top approach to describe a frozen H 3 + as an equilateral triangle. Results. We derive rotational excitation collision rate coefficients of H 3 + with atomic hydrogen in a temperature range corresponding to diffuse interstellar conditions up to ( J, K , ±) = (7, 6, +) and ( J, K , ±) = (6, 4, +) for its ortho and para forms. This allows us to obtain a consistent set of collisional excitation rate coefficients and to improve on a previous study that included speculations regarding these contributions. Conclusions. The new state-specific inelastic H 3 + + H rate coefficients yield differences of up to 20% in the excitation temperature, and their impact increases with decreasing molecular fraction. We also confirm the impact of chemical state-to-state destruction reactions on the excitation balance of H 3 + , and that reactive H + H 3 + collisions are also needed to account for possible further ortho to para transitions. Physics ; Excitation ; Collision ; Astrophysics ; Inelastic collision ; Atomic physics ; Collisional excitation ; Excitation temperature ; Astronomy ; Emission spectrum ; Nuclear physics ; Spectral line ; Ionization ; Ion Spectroscopy and Laser Applications ; Laser Design and Applications ; Gas Dynamics and Kinetic Theory
Authors: Huiyu Li | Lin Zhao | Guangwei Chen | Guoqing Hu | Zhehai Zhou
Source: Photonics (article, 2024-10-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Multilayer Metamaterials with Vertical Cavities for High-Efficiency Transmittance with Metallic Components in the Visible Spectrum Metasurfaces are opening promising flexibilities to reshape the wavefront of electromagnetic waves. Notable optical phenomena are observed with the tailored surface plasmon, which is excited by metallic components in the visible spectrum. However, metamaterial or metasurface devices utilizing metallic materials encounter the challenge of low transmission efficiency, particularly within the visible spectrum. This study proposes a multilayer design strategy to enhance their transmission efficiency. By incorporating additional metal layers for improvements in the transmission efficiency and dielectric layers as spacers, cavities are formed along the propagation direction, enabling the modulation of transmittance and reflection through a process mimicking destructive interference. An analytical model simplified with the assumption of deep-subwavelength-thick metal layers is proposed to predict the structural parameters with optimized transmittance. Numerical studies employing the rigorous coupled wave analysis method confirmed that the additional metal layers significantly improve the transmittance. The introduction of the extra metal and dielectric layers enhances the transmission efficiency in specific spectral regions, maintaining a controllable passband and transmittance. The results indicate that the precise control over the layers’ thicknesses facilitates the modulation of peak-to-valley ratios and the creation of comb-like filters, which can be further refined through controlled random variation in the thickness. Furthermore, when the thickness of the silver layer followed an arithmetic sequence, a multilayer structure with a transmittance of approximately 80% covering the entire visible spectrum could be achieved. Significantly, the polarization extinction ratio and the phase delay of the incident beams could still be modulated by adjusting the geometrical structure and parameters of the multilayer metamaterial for diversified functionalities. Transmittance ; Materials science ; Metamaterial ; Visible spectrum ; Optoelectronics ; Optics ; Physics Metamaterials and Metasurfaces Applications ; Optical Wireless Communication Technologies ; Advanced Antenna and Metasurface Technologies
Authors: Esmaeil Shahryari | María Cecilia Poletti | Dalibor Preisler | Petr Harcuba | Josef Stráský | Miloš Janeček | Fernando Warchomicka
Source: Journal of Materials Research and Technology (article, 2024-11-01)
Field: Materials Science — Materials Chemistry

Heterogeneous dynamic restoration of Ti–15Mo alloy during hot compression Near-β titanium alloys have shown low Young's modulus and good strength, making them excellent implant candidates. However, their processing using thermomechanical routes in single phase β region results in heterogeneous microstructures due to high content alloying elements and consequent slow diffusion-controlled processes such as dynamic recovery. This study investigates the deformation behaviour of a Ti–15Mo alloy through hot compression experiments using a Gleeble ® 3800 device in the single β domain at strain rates from 0.01 s −1 to 10 s −1 , reaching final strains of 0.50 and 0.85 followed by immediate water quench. The findings show that the material presents a low strain rate sensitivity. The flow curves show significant strain hardening before reaching a steady-state regime, particularly at high strain rates. The strain hardening exponent calculations support the effect of molybdenum on retarding softening mechanisms such as dynamic recovery. Electron backscatter diffraction (EBSD) measurements of deformed samples revealed that dynamic recovery is the primary restoration mechanism, with continuous and geometric dynamic recrystallisation evidence. Due to the slow restoration process, we observe the subgrain formation for different deformation parameters. Therefore, we introduced an EBSD-based method to quantify dynamic recovery and subgrain size. We concluded that for a given deformation, the areas of dynamically recovered and recrystallised regions decrease with increasing strain rate and decreasing temperature, exhibiting negligible variation at higher strain rates. • Flow curves with broad strain hardening indicate delayed dynamic recovery. • Dynamic recovery followed by continuous and geometric dynamic recrystallisation. • A new EBSD-based method proposed to quantify the restoration mechanisms. • Molybdenum atoms slow down the restoring mechanisms, causing fine subgrains to form. • Subgrains form as a necklace near grain boundaries, extending inwards into the grain. Materials science ; Alloy ; Compression (physics) ; Metallurgy ; Composite material Titanium Alloys Microstructure and Properties ; Metallurgy and Material Forming ; Intermetallics and Advanced Alloy Properties
Authors: Ahmad Beng Hong Kueh | Lim Fong Isabel | Achmad Syafiuddin | Rosmina Ahmad Bustami
Source: Journal of Advanced Research Design (article, 2024-12-09)
Field: Chemistry — Organic Chemistry

Tensegrity Prediction of E. coli Deactivation by Sonication Strategy Bacterial infections continue to pose a significant challenge to public health especially in clean drinking water production. Hence, it is crucial to have effective methods for their elimination. The successful deactivation of bacteria like E. coli through emerging sonic means depends on the identification of their resonant frequencies. However, the conventional approach of determining these frequencies through labor-intensive physical experimentation can be both time-consuming and expensive. This article introduces an innovative approach to determining the resonant frequency of E. coli using a specifically designed tensegrity model that incorporates spectral element formulation. This model, which conforms to the shape of E. coli, enables the calculation of resonant frequencies without the need for time-consuming simulations of element sensitivity. To address the challenges associated with rigid body motion, a small incremental operation is employed to compute the system determinant. The resonant frequencies obtained from the model are shown to align excellently with existing experimental findings. Furthermore, the model reveals that alterations in the geometry of E. coli have a substantial impact on the frequency of deactivation, while other parameters such as density have less influence. The proposed tensegrity model is a potent technique that can rapidly and accurately identify resonant frequencies, thereby enabling instantaneous and more efficient bacterial deactivation, especially during periods of health emergencies. Sonication ; Tensegrity ; Chemistry ; Biological system ; Biochemical engineering ; Computer science ; Chromatography ; Structural engineering ; Engineering ; Biology Polydiacetylene-based materials and applications ; Structural Analysis and Optimization
Authors: Qingqing Zhang | Rongrong Li | Lin Yang | Weiwei Zhao | Qiang Lin | Lei Ouyang | Shengjiang Pang | Huahao Zeng
Source: Journal of Fungi (article, 2024-08-09)
Field: Chemistry — Organic Chemistry

Dynamics of Physiological Properties and Endophytic Fungal Communities in the Xylem of Aquilaria sinensis (Lour.) with Different Induction Times Xylem-associated fungus can secrete many secondary metabolites to help <i>Aquilaria</i> trees resist various stresses and play a crucial role in facilitating agarwood formation. However, the dynamics of endophytic fungi in <i>Aquilaria sinensis</i> xylem after artificial induction have not been fully elaborated. Endophytic fungi communities and xylem physio-biochemical properties were examined before and after induction with an inorganic salt solution, including four different times (pre-induction (0M), the third (3M), sixth (6M) and ninth (9M) month after induction treatment). The relationships between fungal diversity and physio-biochemical indices were evaluated. The results showed that superoxide dismutase (SOD) and peroxidase (POD) activities, malondialdehyde (MDA) and soluble sugar content first increased and then decreased with induction time, while starch was heavily consumed after induction treatment. Endophytic fungal diversity was significantly lower after induction treatment than before, but the species richness was promoted. Fungal β-diversity was also clustered into four groups according to different times. Core species shifted from rare to dominant taxa with induction time, and growing species interactions in the network indicate a gradual complication of fungal community structure. Endophytic fungi diversity and potential functions were closely related to physicochemical indices that had less effect on the relative abundance of the dominant species. These findings help assess the regulatory mechanisms of microorganisms that expedite agarwood formation after artificial induction. Xylem ; Biology ; Botany ; Plant use of endophytic fungi in defense Wood and Agarwood Research ; Microbial Metabolism and Applications ; Tea Polyphenols and Effects
Authors: Diniz Carvalho de Arruda | Jorge Ricardo Ducati | Pâmela Aude Pithan | Adriane Brill Thum | Rosemary Hoff
Source: Ciência Rural (article, 2024-03-01)
Field: Chemistry — Analytical Chemistry

Hyperspectral data analysis for chlorophyll content derivation in vineyards RESUMO: A qualidade e a produtividade de um vinhedo estão relacionadas com a biomassa do dossel e o vigor foliar, e técnicas de sensoriamento próximo têm sido utilizadas como alternativas aos métodos convencionais para estimar esses parâmetros. O conhecimento do teor de clorofila é fundamental para as avaliações fitossanitárias. No entanto, índices de clorofila também podem ser extraídos de espectros de refletância obtidos para uma ampla gama de aplicações. Nesta perspectiva, foram investigadas as relações entre os índices de clorofila obtidos por medidas diretas e derivados de radiometria de campo, com o objetivo de avaliar a acurácia do teor de clorofila previsto. A investigação foi realizada em plantas da variedade Cabernet Sauvignon, baseando-se em levantamentos diretos de clorofila, espectrorradiometria foliar e na derivação de Índices de Vegetação Hiperespectrais (HVIs), sendo a aquisição de dados realizada em duas fases do ciclo vegetativo. Os resultados das estimativas mostraram que os maiores coeficientes de determinação expressando a correlação entre medições e predições foram obtidas para Chl a e Chl a/Chl b modeladas pelo algoritmo RFR, com valores de R ² tão altos quanto 0,8 e erros quadráticos médios tão baixos quanto 0,093. Com relação aos HVIs, o Photochemical Reflectance Index (PRI) calculado para a segunda data de aquisição, correspondente às folhas que atingiram a senescência, foi o que produziu o maior percentual de explicações de predição. Em conclusão, sugere-se que este estudo pode trazer uma contribuição significativa para o desenvolvimento de técnicas não invasivas de monitoramento de vinhedos. Hyperspectral imaging ; Chlorophyll ; Environmental science ; Remote sensing ; Mathematics ; Botany ; Biology ; Geography Spectroscopy and Chemometric Analyses ; Remote Sensing in Agriculture ; Horticultural and Viticultural Research
Authors: Hong Yin | Ziqiang Chen | Yafei Chen | Hua Tan | Mingyuan Wang | Donglin He | Ping Ouyang | Haifeng Gong
Source: ACS Omega (article, 2024-05-01)
Field: Chemistry — Analytical Chemistry

Comprehensive Understanding of the Heavy Oil Combustion Process: Reaction Behavior, Kinetic Triplet, and Mechanism Implication In this work, thermo-oxidative behavior, kinetic triplet, and free radical mechanism of ultraheavy oil during an in situ combustion (ISC) process were systematically surveyed via multiple thermal analysis techniques (TG/DTG/DSC/PDSC), model-free methods, and related mathematical simulation. First, specific mass loss, exothermic intensity, and corresponding temperature intervals were respectively determined in low-/high-temperature oxidation (LTO/HTO) regions. In addition, the comparison of atmospheric/pressurized differential scanning calorimetry (DSC/PDSC) experiments indicated that the pressurized conditions could obviously strengthen the oxidation progress with more heat emission. Then two model-free methods were contrastively employed for PDSC data to calculate LTO and HTO activation energy variations with the conversion rate. Moreover, the acceleratory rate model for LTO and the Sestak-Berggren model for HTO were accordingly picked as the most probable mechanism functions, which were later used to determine the simulated curves. Then, the simulations of α-<i>T</i> and dα/d<i>T</i>-<i>T</i> curves were respectively attained using Friedman equation in MATLAB software and contrasted with experimental data to validate the accuracy of the yielded kinetic triplet and forecast the combustion behavior. Further, the evolution pathways of the underlying oxidation mechanism was illustrated. This study updates the understanding of the nonisothermal combustion process, contributing to the subsequent numerical simulation and feasible investigation for in situ combustion implementation to enhance heavy oil recovery. Mechanism (biology) ; Process (computing) ; Combustion ; Kinetic energy ; Chemistry ; Biochemical engineering ; Computer science ; Physical chemistry ; Engineering ; Physics ; Epistemology ; Classical mechanics ; Philosophy Petroleum Processing and Analysis ; Thermal and Kinetic Analysis ; Thermochemical Biomass Conversion Processes
Authors: Anita Mongshi | Yves Armand Tene Deffo | Nicolas Mary | Pierre Tsafack | Jean-François Mogniotte | Benjamin Ducharne
Source: Journal of Magnetism and Magnetic Materials (article, 2024-11-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Magnetization mechanisms for non-destructive evaluation of low-carbon steels subject to early-stage low-temperature thermal oxidation Materials science ; Magnetization ; Stage (stratigraphy) ; Carbon fibers ; Thermal ; Subject (documents) ; Nuclear magnetic resonance ; Condensed matter physics ; Composite material ; Magnetic field ; Computer science ; Thermodynamics ; Physics ; Composite number Magnetic Properties and Applications ; Non-Destructive Testing Techniques ; Microstructure and Mechanical Properties of Steels