jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Simón Roa | Terunori Kaihara | María L. Pedano | Henrik Parsamyan | P. Vavassori
Source: Nanoscale (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Laser polarization as a critical factor in the SERS-based molecular sensing performance of nano-gapped Au nanowires Nowadays, Au dimer-based nanostructures are exhaustively studied due to their outstanding potential as plasmonic nanoantennas for future applications in high-sensitivity molecular sensing by Surface-Enhanced Raman Spectroscopy (SERS). In this work, we analyze nano-gapped Au nanowires (NWs) or Au-NW dimers for designing efficient nanoantennas, reporting an exhaustive study about dimer length and laser polarization orientation effects on their SERS-based molecular sensing performance. Arrays of nanoantennas with gaps of about 22 ± 4 nm, nominal square cross-sections of 60 nm × 60 nm, and different segment lengths from 300 nm up to 1200 nm were fabricated by Au evaporation and subsequent e-beam lithography. The SERS performance was studied by confocal Raman microscopy using a linearly-polarized 633 nm laser. A critical impact of the polarization alignment on the spectral resolution of the studied Raman marker imprint was observed. The results show that the Raman signal is maximized by aligning the polarization orientation with the nanowire long axis, it is reduced by increasing the relative angle, and it is abruptly minimized when both are perpendicular. These observations were consistent with numerical simulations carried out by the FDTD method, which predicts a similar dependence between the orientation of linearly-polarized light and electric-near field amplification in the nano-gap zone. Our results provide an interesting paradigm and relevant insights in determining the role of laser polarization in the Raman signal enhancement in nano-gapped Au nanowires, showing the key role of this measurement condition on the SERS-based molecular sensing efficiency of this kind of nanostructure. Nano- ; Materials science ; Polarization (electrochemistry) ; Laser ; Nanowire ; Nanotechnology ; Nanoscopic scale ; Optoelectronics ; Optics ; Physics ; Chemistry ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Nanowire Synthesis and Applications
Authors: Hao Zhang | Yang Liu | Xiaoyan Liu | Cheng Wang | Maozu Guo
Source: BMC Bioinformatics (article, 2024-05-30)
Field: Materials Science — Materials Chemistry

Equivariant score-based generative diffusion framework for 3D molecules Through the experiments and comparative results, our framework clearly outperforms previous 3D molecular generation methods, exhibiting significantly better capacity for modeling chemically realistic molecules. The excellent performance of EMDS in 3D molecular generation brings novel and encouraging opportunities for tackling challenging biomedical molecule and protein scenarios. Equivariant map ; Generative grammar ; Computer science ; DNA microarray ; Diffusion ; Computational biology ; Biology ; Natural language processing ; Mathematics ; Artificial intelligence ; Physics ; Genetics ; Pure mathematics Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Protein Structure and Dynamics
Authors: Ioannis Papagiannis | Mauro S. Innocente | Joshua D. Davies | Joshua L. Ryan | Evangelos I. Gkanas
Source: Fire Safety Journal (article, 2024-11-14)
Field: Materials Science — Materials Chemistry

Investigating the impact of iron oxide nanoparticles on the stability of class A foam for wildfire suppression This study investigates the effect of Iron Oxide Nanoparticles (IONPs) on the stability of a class A foam. IONPs are synthesised via two different pathways, namely the reflux and the hydrothermal methods. The synthesised nanoparticles are then added to the foam solution at different concentrations, applying various techniques to test how they affect properties and processes such as particle size distribution, surface tension, and coalescence. Results show that ( i ) the addition of IONPs improves the foam stability by reducing the bubble coarsening and disproportionation; ( i i ) the IONPs assemble at the plateau borders and nodes of the bubbles creating a protective layer on the gas–liquid interface, which delays foam drainage hence improving foam stability; and ( i i i ) stability is also improved by the increase in the foam half-life due to the accumulation of nanoparticles on the surface of the bubble. IONPs obtained using the reflux method are shown to affect the firefighting foam more positively. • Iron Oxide Nanoparticles (IONPs) improve foam stability by altering bubble structure. • IONPs also improve foam stability by altering surface tension. • Reflux is more cost-effective and practical than hydrothermal synthesis in the lab. • X-ray Diffraction (XRD) analysis confirms crystalline structure of synthesised IONPs. • A crystalline structure is indicative of their potential to enhance foam stability. Class (philosophy) ; Nanoparticle ; Stability (learning theory) ; Iron oxide nanoparticles ; Iron oxide ; Poison control ; Environmental science ; Engineering ; Forensic engineering ; Materials science ; Computer science ; Chemical engineering ; Medical emergency ; Medicine Pickering emulsions and particle stabilization ; Enhanced Oil Recovery Techniques ; Heat and Mass Transfer in Porous Media
Authors: Juan Botero-Valencia | Erick Reyes-Vera | Elizabeth Ospina-Rojas | Flavio Prieto
Source: Instruments (article, 2024-03-17)
Field: Chemistry — Analytical Chemistry

A Portable Tool for Spectral Analysis of Plant Leaves That Incorporates a Multichannel Detector to Enable Faster Data Capture In this study, a novel system was designed to enhance the efficiency of data acquisition in a portable and compact instrument dedicated to the spectral analysis of various surfaces, including plant leaves, and materials requiring characterization within the 410 to 915 nm range. The proposed system incorporates two nine-band detectors positioned on the top and bottom of the target surface, each equipped with a digitally controllable LED. The detectors are capable of measuring both reflection and transmission properties, depending on the LED configuration. Specifically, when the upper LED is activated, the lower detector operates without its LED, enabling the precise measurement of light transmitted through the sample. The process is reversed in subsequent iterations, facilitating an accurate assessment of reflection and transmission for each side of the target surface. For reliability, the error estimation utilizes a color checker, followed by a multi-layer perceptron (MLP) implementation integrated into the microcontroller unit (MCU) using TinyML technology for real-time refined data acquisition. The system is constructed with 3D-printed components and cost-effective electronics. It also supports USB or Bluetooth communication for data transmission. This innovative detector marks a significant advancement in spectral analysis, particularly for plant research, offering the potential for disease detection and nutritional deficiency assessment. Detector ; Computer science ; Spectral analysis ; Remote sensing ; Physics ; Geography ; Telecommunications ; Spectroscopy Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Leaf Properties and Growth Measurement
Authors: Andrew F. Worrall | Craig D. Campbell | Megan O. Midson | Malcolm I. Stewart
Source: Rapid Communications in Mass Spectrometry (article, 2024-06-30)
Field: Chemistry — Spectroscopy

University teaching of mass spectrometry as a key practical technique within the context of a fully integrated, spiral curriculum APCI-MS has proven to be an easy-to-use and valuable addition to our undergraduate practical course. The robustness of the spectrometer enables routine use by large cohorts of students with minimal supervision, and routine maintenance can be carried out by non-specialist technicians. Students can readily process and interpret results for a series of routine analyses, as well as demonstrate uses in problem-solving exercises. Context (archaeology) ; Curriculum ; Key (lock) ; Mass spectrometry ; Spiral (railway) ; Computer science ; Engineering ; Psychology ; Chemistry ; Pedagogy ; History ; Chromatography ; Mechanical engineering ; Computer security ; Archaeology Mass Spectrometry Techniques and Applications ; Nuclear Physics and Applications ; Analytical Chemistry and Chromatography
Authors: Tao Yue | Yuhan Gao | Baoxi Zhang | Kun Hu | Yifei Xie | Li Zhang | Shiying Yang | Yang Lü
Source: Crystals (article, 2024-12-30)
Field: Chemistry — Spectroscopy

Advances in Quantitative Analytical Methods for Solid Drugs The solid form of the drug can directly affect the physicochemical properties, bioavailability, safety, and efficacy of the drug, and its types mainly include amorphous state, single-component polycrystalline, hydrate, solvate, salt, and cocrystal. Polymorphic drugs are solid drugs whose active ingredients exist in a specific crystalline state. Polymorphic drugs are solid drugs whose active ingredients exist in a specific crystalline state. Drug polymorphism refers to the presence of two or more different crystalline states of the drug. Pharmaceutical cocrystal is a new type of solid form that can improve the stability, solubility, and bioavailability of active pharmaceutical ingredients and many other physicochemical properties. The determination of the crystalline form of a drug and its content is of great significance in ensuring the quality of the polymorphic drug and its safety. In this paper, the quantitative analysis methods of polymorphs and pharmaceutical cocrystals are reviewed, the advantages and disadvantages of various methods are analyzed mainly from three types of techniques, namely, X-ray diffraction, spectroscopy, and thermal analysis, and the specific applications of various methods are commented on through examples. The analytical methods that can effectively determine the content of polymorphic drugs are comprehensively mastered to provide a reference for the establishment of quality standards for polymorphic drugs. Computer science ; Management science ; Biochemical engineering ; Engineering Analytical Chemistry and Chromatography ; Drug Solubulity and Delivery Systems ; Analytical Methods in Pharmaceuticals
Authors: Anthony Trubiano | Michael F. Hagan
Source: Physical Review X (article, 2024-12-10)
Field: Materials Science — Materials Chemistry

Markov State Model Approach to Simulate Self-Assembly Computational modeling of assembly is challenging for many systems, because their timescales can vastly exceed those accessible to simulations. This article describes the multiMSM, which is a general framework that uses Markov state models (MSMs) to enable simulating self-assembly and self-organization of finite-sized structures on timescales that are orders of magnitude longer than those accessible to brute-force dynamics simulations. As with traditional MSM approaches, the method efficiently overcomes free energy barriers and other dynamical bottlenecks. In contrast to previous MSM approaches to simulating assembly, the framework describes simultaneous assembly of many clusters and the consequent depletion of free subunits or other small oligomers. The algorithm accounts for changes in transition rates as concentrations of monomers and intermediates evolve over the course of the reaction. Using two model systems, we show that the multiMSM accurately predicts the concentrations of the full ensemble of intermediates on timescales required to reach equilibrium. Importantly, after constructing a multiMSM for one system concentration, yields at other concentrations can be approximately calculated without any further sampling. This capability allows for orders of magnitude additional speedup. In addition, the method enables highly efficient calculation of quantities such as free energy profiles, nucleation timescales, flux along the ensemble of assembly pathways, and entropy production rates. Identifying contributions of individual transitions to entropy production rates reveals sources of kinetic traps. The method is broadly applicable to systems with equilibrium or nonequilibrium dynamics and is trivially parallelizable and, thus, highly scalable. Published by the American Physical Society 2024 Computer science ; State (computer science) ; Statistical physics ; Markov chain ; Distributed computing ; Algorithm ; Physics ; Machine learning Pickering emulsions and particle stabilization ; Modular Robots and Swarm Intelligence ; Micro and Nano Robotics
Authors: Mohamed Diaf | H. Righi | Raouf Beddiaf | Y. Djaballah | H. Rached
Source: Canadian Journal of Physics (article, 2024-09-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Ab initio investigation of the structural, mechanical, electronic, thermodynamic, and optical properties of V<sub>2</sub>FeNiGe<sub>2</sub> and Hf<sub>2</sub>FeNiSb<sub>2</sub> double half-Heusler compounds In the present work, using ab initio density-functional theory methods based on the Quantum ESPRESSO package, we have investigated the structural, elastic, electronic, and optical properties of 18-electron V 2 FeNiGe 2 and Hf 2 FeNiSb 2 double half-Heusler alloys. The calculated elastic properties suggest a ductile behavior with metallic bonding for V 2 FeNiGe 2 and a brittle behavior with covalent bonding for Hf 2 FeNiSb 2 . The thermodynamic properties (Debye temperature, melting temperature) are also predicted and discussed for the studied alloys. The alloys are found to be semiconducting with indirect band gaps of 0.53 eV for V 2 FeNiGe 2 and 0.47 eV for Hf 2 FeNiSb 2 . We also computed and analyzed their optical properties (dielectric function, optical conductivity, refractive index, absorption index, and reflectance) and our calculations suggest that both materials have high absorption coefficient and optical conductivity in the UV as well as visible region. The results make them potential candidates for the manufacture of opto-electronic devices. Physics ; Ab initio ; Condensed matter physics ; Thermodynamics ; Quantum mechanics Heusler alloys: electronic and magnetic properties ; Intermetallics and Advanced Alloy Properties ; Inorganic Chemistry and Materials
Authors: Mauricio J. del Razo | Daan Crommelin | Peter G. Bolhuis
Source: The Journal of Chemical Physics (article, 2024-01-09)
Field: Materials Science — Materials Chemistry

Data-driven dynamical coarse-graining for condensed matter systems Simulations of condensed matter systems often focus on the dynamics of a few distinguished components but require integrating the full system. A prime example is a molecular dynamics simulation of a (macro)molecule in a solution, where the molecule(s) and the solvent dynamics need to be integrated, rendering the simulations computationally costly and often unfeasible for physically/biologically relevant time scales. Standard coarse graining approaches can reproduce equilibrium distributions and structural features but do not properly include the dynamics. In this work, we develop a general data-driven coarse-graining methodology inspired by the Mori-Zwanzig formalism, which shows that macroscopic systems with a large number of degrees of freedom can be described by a few relevant variables and additional noise and memory terms. Our coarse-graining method consists of numerical integrators for the distinguished components, where the noise and interaction terms with other system components are substituted by a random variable sampled from a data-driven model. The model is parameterized using data from multiple short-time full-system simulations, and then, it is used to run long-time simulations. Applying our methodology to three systems-a distinguished particle under a harmonic and a bistable potential and a dimer with two metastable configurations-the resulting coarse-grained models are capable of reproducing not only the equilibrium distributions but also the dynamic behavior due to temporal correlations and memory effects. Remarkably, our method even reproduces the transition dynamics between metastable states, which is challenging to capture correctly. Our approach is not constrained to specific dynamics and can be extended to systems beyond Langevin dynamics, and, in principle, even to non-equilibrium dynamics. Granularity ; Statistical physics ; Parameterized complexity ; Computer science ; Integrator ; Bistability ; Non-equilibrium thermodynamics ; Metastability ; Degrees of freedom (physics and chemistry) ; Molecular dynamics ; Physics ; Algorithm ; Quantum mechanics Block Copolymer Self-Assembly ; Protein Structure and Dynamics ; Machine Learning in Materials Science
Authors: Yuemin Liu | Yunxiang Gao | Tariq Altalhi | Di‐Jia Liu | Boris I. Yakobson
Source: Nanomaterials (article, 2024-09-29)
Field: Chemistry — Organic Chemistry

A Quantum Mechanical MP2 Study of the Electronic Effect of Nonplanarity on the Carbon Pyramidalization of Fullerene C60 Among C<sub>60</sub>'s diverse functionalities, its potential application in CO<sub>2</sub> sequestration has gained increasing interest. However, the processes involved are sensitive to the molecule's electronic structure, aspects of which remain debated and require greater precision. To address this, we performed structural optimization of fullerene C<sub>60</sub> using the QM MP2/6-31G* method. The nonplanarity of the optimized icosahedron is characterized by two types of dihedral angles: 138° and 143°. The 120 dihedrals of 138° occur between two hexagons intersecting at C-C bonds of 1.42 Å, while the 60 dihedrals of 143° are observed between hexagons and pentagons at C-C bonds of 1.47 Å. NBO analysis reveals less pyramidal sp<sup>1.78</sup> hybridization for carbons at the 1.42 Å bonds and more pyramidal sp<sup>2.13</sup> hybridization for the 1.47 Å bonds. Electrostatic potential charges range from -0.04 a.u. to 0.04 a.u. on the carbon atoms. Second-order perturbation analysis indicates that delocalization interactions in the C-C bonds of 1.42 Å (143.70 kcal/mol) and 1.47 Å (34.98 kcal/mol) are 22% and 38% higher, respectively, than those in benzene. MP2/Def2SVP calculations yield a correlation energy of 13.49 kcal/mol per electron for C<sub>60</sub>, slightly higher than the 11.68 kcal/mol for benzene. However, the results from HOMO-LUMO calculations should be interpreted with caution. This study may assist in the rational design of fullerene C<sub>60</sub> derivatives for CO<sub>2</sub> reduction systems. Fullerene ; Carbon fibers ; Quantum ; Materials science ; Computational chemistry ; Chemistry ; Physics ; Organic chemistry ; Quantum mechanics ; Composite number Fullerene Chemistry and Applications ; Carbon Nanotubes in Composites ; Graphene research and applications
Authors: Chao Lv | De‐Li Chen
Source: ChemCatChem (article, 2024-07-29)
Field: Chemistry — Inorganic Chemistry

Theoretical Understandings on Mechanisms of Hydrogenation Activities Using Graphene‐Based Single‐Atom Catalysts Abstract Metal single‐atom catalysts (SACs) have emerged as a promising class of catalysts in various fields, owing to their well‐defined active centers, tunable coordination environments, and high reaction selectivity. Among the diverse supports, graphene‐based SACs have garnered significant attention due to their exceptional properties in hydrogenation reactions. This review elucidates recent advancements in theoretical investigations of the electronic and geometric structures of metal SACs, with a focus on modulation strategies such as coordination number adjustment, heteroatom doping, defect site engineering, and frustrated Lewis pair construction. This review emphasizes atomic‐level insights into the hydrogenation reaction mechanism in thermocatalysis, including the activation of the H‐source molecules, hydrogen diffusion, and elementary reaction steps. Strategies for modulating the catalytic activity of SACs are summarized. Lastly, this review offers perspectives on the design of effective graphene‐based SACs from theoretical standpoint, paving the way for future research in this exciting field. Graphene ; Catalysis ; Atom (system on chip) ; Nanotechnology ; Chemistry ; Materials science ; Computational chemistry ; Combinatorial chemistry ; Chemical physics ; Organic chemistry ; Computer science ; Parallel computing Asymmetric Hydrogenation and Catalysis ; Nanomaterials for catalytic reactions ; Catalysis and Hydrodesulfurization Studies
Authors: Sanjay Kumar Rout | Jagannath Panda | Vishal Gavande | Prasan Kumar Panda | Shahid Anwar | Sony Pandey | Bankim Chandra Tripathy
Source: Discover Polymers. (review, 2024-10-14)
Field: Materials Science — Polymers and Plastics

A cutting-edge review emphasizing the key approaches for chemical transformation of lignocellulosic fibers for viable engineering composites Composite materials play a crucial role in the expanding high-tech world by enabling lighter, stronger, and more durable products while offering enhanced design flexibility and performance characteristics. They are very important materials for aerospace, automobile, marine, electronic and telecommunications, health care etc. Composite materials pose environmental concerns like resource intensity, raw material sourcing, waste generation, high energy consumption, use of toxic chemicals during manufacturing, thus require introduction of bio based materials during manufacturing to reduce environmental carbon footprints. Replacing fossil fuels with agro-wastes such as lignocellulosic fibers (LCFs) in making composites supports sustainable development goals by mitigating climate change, reducing waste, improving resource efficiency, and promoting environmental stewardship. It represents a significant step towards building a more sustainable and resilient economy. However, due to the incompatibility between hydrophilic nature of the LCFs and hydrophobic thermoplastics the composites damage and issues like moisture absorption, dimensional instability and degradation of mechanical properties arise. One of the ways to deal with the incompatibility is surface modification of the LCFs. Chemical modification increases the hydrophobicity of LCFs hence results in better reinforcing for fabricating defect free composite materials. This article is a comprehensive review of LCFs-reinforced composites based on diverse surface modification techniques with varied chemicals that improve the requisite properties of the composites. Materials science ; Composite material ; Enhanced Data Rates for GSM Evolution ; Key (lock) ; Transformation (genetics) ; Fiber ; Engineering ; Computer science ; Chemistry Natural Fiber Reinforced Composites ; Advanced Cellulose Research Studies ; biodegradable polymer synthesis and properties