jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Bhagoji Bapurao Sul | K. Dhanalakshmi | Seung‐Bok Choi
Source: Sensors (article, 2023-02-22)
Field: Materials Science — Materials Chemistry

Self-Sensing Variable Stiffness Actuation of Shape Memory Coil by an Inferential Soft Sensor Self-sensing actuation of shape memory alloy (SMA) means to sense both mechanical and thermal properties/variables through the measurement of any internally changing electrical property such as resistance/inductance/capacitance/phase/frequency of an actuating material under actuation. The main contribution of this paper is to obtain the stiffness from the measurement of electrical resistance of a shape memory coil during variable stiffness actuation thereby, simulating its self-sensing characteristics by developing a Support Vector Machine (SVM) regression and nonlinear regression model. Experimental evaluation of the stiffness of a passive biased shape memory coil (SMC) in antagonistic connection, for different electrical (like activation current, excitation frequency, and duty cycle) and mechanical input conditions (for example, the operating condition pre-stress) is done in terms of change in electrical resistance through the measurement of the instantaneous value. The stiffness is then calculated from force and displacement, while by this scheme it is sensed from the electrical resistance. To fulfill the deficiency of a dedicated physical stiffness sensor, self-sensing stiffness by a Soft Sensor (equivalently SVM) is a boon for variable stiffness actuation. A simple and well-proven voltage division method is used for indirect stiffness sensing; wherein, voltages across the shape memory coil and series resistance provide the electrical resistance. The predicted stiffness of SVM matches well with the experimental stiffness and this is validated by evaluating the performances such as root mean squared error (RMSE), the goodness of fit and correlation coefficient. This self-sensing variable stiffness actuation (SSVSA) provides several advantages in applications of SMA: sensor-less systems, miniaturized systems, simplified control systems and possible stiffness feedback control. Stiffness ; Voltage ; Electromagnetic coil ; Shape-memory alloy ; Engineering ; Control theory (sociology) ; Structural engineering ; Acoustics ; Materials science ; Computer science ; Electrical engineering ; Composite material ; Artificial intelligence Shape Memory Alloy Transformations ; Structural Health Monitoring Techniques ; Smart Materials for Construction
Authors: V.S. Shiryaev | А.P. Velmuzhov | Т.V. Kotereva | E.A. Tyurina | М.В. Суханов | E.V. Karaksina
Source: Fibers (article, 2023-06-16)
Field: Chemistry — Spectroscopy

Recent Achievements in Development of Chalcogenide Optical Fibers for Mid-IR Sensing Recent results of research of passive and active optical waveguides made of high-purity chalcogenide glasses for middle infrared fiberoptic evanescent wave spectroscopy of liquid and gaseous substances are presented. On the basis of selenide and telluride glass fibers, novel types of highly sensitive fiber probes are developed. On the basis of Pr(3+)- and Tb(3+)-doped Ga(In)-Ge-As-Se and Ga-Ge-Sb-Se glass fibers, the 4.2–6 μm wavelength radiation sources are created for all-fiber sensor systems. Successful testing of chalcogenide glass fiber sensors for the analysis of some liquid and gaseous mixtures was carried out. Chalcogenide ; Chalcogenide glass ; Materials science ; Selenide ; Optical fiber ; Optoelectronics ; Fiber ; Telluride ; Infrared ; Optics ; Glass fiber ; Composite material Spectroscopy and Laser Applications ; Phase-change materials and chalcogenides ; Photonic Crystal and Fiber Optics
Authors: Sarah J. Gray | Martin Walker | Rachel L. Hendrikse | Mark R. Wilson
Source: Soft Matter (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

Investigating anionic surfactant phase diagrams using dissipative particle dynamics: development of a transferable model Dissipative particle dynamics (DPD) provides a powerful coarse-grained simulation technique for the study of a wide range of soft matter systems. Here, we investigate the transferability of DPD models to the prediction of anionic surfactant phase diagrams, taking advantage of fast parameter sweeps to optimise the choice of DPD parameters for these systems. Parameters are developed which provide a good representation of the phase diagrams of SDS (sodium dodecyl sulfate) and three different isomeric forms of LAS (linear alkylbenzene sulfonates) across an extensive concentration range. A high degree of transferability is seen, with parameters readily transferable to other systems, such as AES (alkyl ether sulfates). Excellent agreement is obtained with experimentally measured quantities, such as the lamellar layer spacing. Isosurfaces are produced from the surfactant head group, from which the second moment <i>M</i> of the isosurface normal distribution is calculated for different phase structures. Lyotropic liquid crystalline phases are characterised by a combination of the eigenvalues of <i>M</i>, radial distribution functions, and visual inspections. Dissipative particle dynamics ; Phase diagram ; Pulmonary surfactant ; Dissipative system ; Phase (matter) ; Particle (ecology) ; Chemical physics ; Statistical physics ; Development (topology) ; Physics ; Materials science ; Thermodynamics ; Geology ; Mathematics ; Polymer Surfactants and Colloidal Systems ; Material Dynamics and Properties ; Spectroscopy and Quantum Chemical Studies
Authors: Ivan R. Sasselli | Ivan Coluzza
Source: Journal of Chemical Theory and Computation (article, 2023-12-19)
Field: Materials Science — Biomaterials

Assessment of the MARTINI 3 Performance for Short Peptide Self-Assembly The coarse-grained MARTINI force field, initially developed for membranes, has proven to be an exceptional tool for investigating supramolecular peptide assemblies. Over the years, the force field underwent refinements to enhance accuracy, enabling, for example, the reproduction of protein-ligand interactions and constant pH behavior. However, these protein-focused improvements seem to have compromised its ability to model short peptide self-assembly. In this study, we assess the performance of MARTINI 3 in reproducing peptide self-assembly using the well-established diphenylalanine (FF) as our test case. Unlike its success in version 2.1, FF does not even exhibit aggregation in version 3. By systematically exploring parameters for the aromatic side chains and charged backbone beads, we established a parameter set that effectively reproduces tube formation. Remarkably, these parameter adjustments also replicate the self-assembly of other di- and tripeptides and coassemblies. Furthermore, our analysis uncovers pivotal insights for enhancing the performance of MARTINI in modeling short peptide self-assembly. Specifically, we identify issues stemming from overestimated hydrophilicity arising from charged termini and disruptions in π-stacking interactions due to insufficient planarity in aromatic groups and a discrepancy in intermolecular distances between this and backbone-backbone interactions. This investigation demonstrates that strategic modifications can harness the advancements offered by MARTINI 3 for the realm of short peptide self-assembly. Stacking ; Peptide ; Planarity testing ; Intermolecular force ; Self-assembly ; Side chain ; Nanotechnology ; Computer science ; Chemistry ; Materials science ; Crystallography ; Molecule ; Polymer Supramolecular Self-Assembly in Materials ; Chemical Synthesis and Analysis ; Antimicrobial Peptides and Activities
Authors: Oscar Bulancea-Lindvall | Joel Davidsson | Rickard Armiento | Igor A. Abrikosov
Source: Physical review. B./Physical review. B (article, 2023-12-07)
Field: Materials Science — Materials Chemistry

Chlorine vacancy in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>4</mml:mn><mml:mi>H</mml:mi><mml:mtext>−</mml:mtext><mml:mi mathvariant="normal">SiC</mml:mi></mml:mrow></mml:math>: An NV-like defect with telecom-wavelength emission The diamond nitrogen vacancy (NV) center remains an ever-increasing topic of interest. At present, it is considered an ideal example of a solid-state qubit applicable in quantum communication, computing, and sensing alike. With its success, the search for defects that share or improve upon its advantageous features is an ongoing endeavor. By performing large-scale high-throughput screening of 52 600 defects in $4H$ silicon carbide (SiC), we identify a collection of NV-like color centers of particular interest. From this list, the single most promising candidate consists of a silicon vacancy and chlorine substituted on the carbon site, and is given the name of chlorine vacancy (ClV) center. Through high-accuracy first-principle calculations, we confirm that the ClV center is similar to the NV center in diamond in its local structure and shares many qualitative and quantitative features in the electronic structure and spin properties. In contrast to the NV center, however, the ClV center in SiC exhibits emission in the telecom range near the C band. Diamond ; Vacancy defect ; Center (category theory) ; Materials science ; Silicon carbide ; Physics ; Algorithm ; Computer science ; Crystallography ; Chemistry ; Condensed matter physics Diamond and Carbon-based Materials Research ; Semiconductor materials and devices ; Metal and Thin Film Mechanics
Authors: Xiaodong Zhang | Chaohui Duan | Yafei Wang | Hongyan Gao | Lian Hu | Xinzhong Wang
Source: Frontiers in Plant Science (article, 2023-01-11)
Field: Chemistry — Analytical Chemistry

Research on a nondestructive model for the detection of the nitrogen content of tomato The timely detection of information on crop nutrition is of great significance for improving the production efficiency of facility crops. In this study, the terahertz (THz) spectral information of tomato plant leaves with different nitrogen levels was obtained. The noise reduction of the THz spectral data was then carried out by using the Savitzky-Golay (S-G) smoothing algorithm. The sample sets were then analyzed by using Kennard-Stone (KS) and random sampling (RS) methods, respectively. The KS algorithm was optimized to divide the sample sets. The stability competitive adaptive reweighted sampling (SCARS), uninformative variable elimination (UVE), and interval partial least-squares (iPLS) algorithms were then used to screen the pre-processed THz spectral data. Based on the selected characteristic frequency bands, a model for the detection of the nitrogen content of tomato based on the THz spectrum was established by the radial basis function neural network (RBFNN) and backpropagation neural network (BPNN) algorithms, respectively. The results show that the root-mean-square error of correction (RMSEC) and root-mean-square error of prediction (RMSEP) of the BPNN model were respectively 0.1722% and 0.1843%, and the determination coefficients of the correction set (<i>R<sub>c</sub></i> <sup>2</sup>) and prediction set (<i>R<sub>p</sub></i> <sup>2</sup>) were respectively 0.8447 and 0.8375. The RMSEC and RMSEP values of the RBFNN model were respectively 0.1322% and 0.1855%, and the <i>R<sub>c</sub></i> <sup>2</sup> and <i>R<sub>p</sub></i> <sup>2</sup> values were respectively 0.8714 and 0.8463. Thus, the accuracy of the model established by the RBFNN algorithm was slightly higher. Therefore, the nitrogen content of tomato leaves can be detected by THz spectroscopy. The results of this study can provide a theoretical basis for the research and development of equipment for the detection of the nitrogen content of tomato leaves. Smoothing ; Partial least squares regression ; Mean squared error ; Mathematics ; Sampling (signal processing) ; Noise (video) ; Statistics ; Algorithm ; Computer science ; Biological system ; Artificial intelligence ; Pattern recognition (psychology) ; Filter (signal processing) Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Terahertz technology and applications
Authors: Lixiu Zhang | Pengcheng Nie | Shujuan Zhang | Liying Zhang | Tianyuan Sun
Source: Foods (article, 2023-09-27)
Field: Chemistry — Analytical Chemistry

Research on Defect Detection in Kubo Peach Based on Hyperspectral Imaging Technology Combined with CARS-MIV-GA-SVM Method Due to the dark red surface of ripe fresh peaches, their internal injury defects cannot be detected using the naked eye and conventional images. The rapid and accurate detection of fresh peach defects can improve the efficiency of fresh peach classification. The goal of this paper was to develop a nondestructive approach to simultaneously detecting internal injury defects and external injuries in fresh peaches. First, we collected spectral data from 347 Kubo peach samples using hyperspectral imaging technology (900-1700 nm) and carried out pretreatment. Four methods (the competitive adaptive reweighting algorithm (CARS), the combination of CARS and the average influence value algorithm (CARS-MIV), the combination of CARS and the successive projections algorithm (CARS-SPA), and the combination of CARS and uninformative variable elimination (CARS-UVE)) were used to extract the characteristic wavelength. Based on the characteristic wavelength extracted using the above methods, a genetic algorithm optimization support vector machine (GA-SVM) model and a least-squares support vector machine (LS-SVM) model were used to establish classification models. The results show that the combination of CARS and other feature wavelength extraction methods can effectively improve the prediction accuracy of the model when the number of wavelengths is small. Among them, the discriminant accuracy of the CARS-MIV-GA-SVM model reaches 93.15%. In summary, hyperspectral imaging technology can accomplish the accurate detection of Kubo peaches defects, and provides feasible ideas for the automatic classification of Kubo peaches. Hyperspectral imaging ; Support vector machine ; Artificial intelligence ; Computer science ; Pattern recognition (psychology) ; Genetic algorithm ; Algorithm ; Machine learning Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Essential Oils and Antimicrobial Activity
Authors: Xin Zhang | Hongbo Lou | Beatrice Ruta | Yuriy Chushkin | Federico Zontone | Shubin Li | Dazhe Xu | Tao Liang | Zhidan Zeng | Ho‐kwang Mao | Qiaoshi Zeng
Source: Proceedings of the National Academy of Sciences (article, 2023-06-05)
Field: Materials Science — Materials Chemistry

Pressure-induced nonmonotonic cross-over of steady relaxation dynamics in a metallic glass Relaxation dynamics, as a key to understand glass formation and glassy properties, remains an elusive and challenging issue in condensed matter physics. In this work, in situ high-pressure synchrotron high-energy X-ray photon correlation spectroscopy has been developed to probe the atomic-scale relaxation dynamics of a cerium-based metallic glass during compression. Although the sample density continuously increases, the collective atomic motion initially slows down as generally expected and then counterintuitively accelerates with further compression (density increase), showing an unusual nonmonotonic pressure-induced steady relaxation dynamics cross-over at ~3 GPa. Furthermore, by combining in situ high-pressure synchrotron X-ray diffraction, the relaxation dynamics anomaly is evidenced to closely correlate with the dramatic changes in local atomic structures during compression, rather than monotonically scaling with either sample density or overall stress level. These findings could provide insight into relaxation dynamics and their relationship with local atomic structures of glasses. Relaxation (psychology) ; Synchrotron ; Compression (physics) ; Amorphous metal ; Materials science ; Dynamics (music) ; Chemical physics ; Diffraction ; Scaling ; Condensed matter physics ; Chemistry ; Physics ; Optics ; Composite material Material Dynamics and Properties ; Glass properties and applications ; Metallic Glasses and Amorphous Alloys
Authors: Nematollah Omidikia | Mahdiyeh Ghaffari | Jeroen J. Jansen | L.M.C. Buydens | Romá Tauler
Source: Chemometrics and Intelligent Laboratory Systems (article, 2023-06-19)
Field: Chemistry — Analytical Chemistry

Bilinear model factor decomposition: A general mixture analysis tool The analysis of mixtures is a routine task in the analytical chemistry area as well as in other research fields. The objective is to identify, quantify, and interpret the chemical components of the mixtures. Various bilinear factor decomposition methods, including MCR-ALS, NMFand BNFA, have been proposed to solve this problem. However, there is little knowledge about their comparative performance in terms of different factors, such as solution reliability, calculation speed, convergence, flexibility in constraint implementation, and ease of results interpretation. To address these issues, this work aims to compare these methods using data examples from data simulations, environmental source apportionment studies, and chromatographic analysis of chemical mixtures. Through this comparison, we hope to gain insights into the strengths and weaknesses of each method and provide recommendations for researchers working in this field. This comprehensive comparison will help researchers choose the appropriate method for their specific analysis needs, ultimately leading to more accurate and efficient analysis. Computer science ; Bilinear interpolation ; Decomposition ; Reliability (semiconductor) ; Constraint (computer-aided design) ; Flexibility (engineering) ; Field (mathematics) ; Strengths and weaknesses ; Factor (programming language) ; Convergence (economics) ; Management science ; Apportionment ; Data mining ; Mathematics ; Statistics ; Chemistry ; Engineering Spectroscopy and Chemometric Analyses ; Analytical Chemistry and Chromatography ; Mass Spectrometry Techniques and Applications
Authors: Mehmet Emin Ergün | İsmail Özlüsoylu | Abdullah İstek | Ahmet Can
Source: Coatings (article, 2023-08-22)
Field: Materials Science — Polymers and Plastics

Analysis and Impact of Activated Carbon Incorporation into Urea-Formaldehyde Adhesive on the Properties of Particleboard Nowadays, the particleboard industry cannot meet the market’s demand. Therefore, filler materials have started to be used both to conserve raw materials and to enable the use of wood-based boards in different areas. This study investigates the effects of incorporating different ratios of activated carbon (0%, 1.5%, 4.5%, 7.5%) on the properties of particleboards. The physical properties were examined, including density, moisture content, thickness swelling, and water absorption. The results reveal that the density increased with increasing activated carbon content while the moisture content decreased, indicating improved dimensional stability and water resistance. Additionally, the color properties were influenced by activated carbon, leading to a darker appearance with decreased lightness and yellow-blue components. The mechanical properties, such as internal bond strength, modulus of rupture, and modulus of elasticity, showed significant enhancements with the addition of activated carbon, indicating improved bonding and increased strength. Moreover, the thermal conductivity decreased with increasing activated carbon content and improved insulation performance. Scanning electron microscope analysis confirmed the uniform distribution of activated carbon within the particleboard matrix, without agglomeration, positively impacting the mechanical performance. According to the thermogravimetric analysis results, the addition of activated carbon led to a decrease of up to 6.15% in mass loss compared to the control group. The incorporation of activated carbon at a ratio of 4.5% in particleboards confers notable enhancement to their physical, mechanical, and thermal characteristics. These findings contribute to understanding the potential benefits and considerations of using activated carbon as an additive in particleboard production. Thermogravimetric analysis ; Materials science ; Activated carbon ; Composite material ; Adhesive ; Equilibrium moisture content ; Young's modulus ; Swelling ; Absorption of water ; Carbon fibers ; Dynamic mechanical analysis ; Thermal stability ; Flexural strength ; Raw material ; Water content ; Chemical engineering ; Polymer ; Chemistry ; Organic chemistry ; Sorption ; Adsorption ; Composite number Natural Fiber Reinforced Composites ; Lignin and Wood Chemistry ; Wood Treatment and Properties
Authors: Rémi Delaporte-Mathurin | Romain Chochoy | Jonathan Mougenot | Y. Charles | E.A. Hodille | C. Grisolia
Source: Nuclear Fusion (article, 2023-11-27)
Field: Materials Science — Materials Chemistry

3D effects on hydrogen transport in ITER-like monoblocks Abstract The influence of recombination on the poloidal gaps of ITER-like monoblocks on hydrogen transport simulations is investigated. A 3D FESTIM model is first built and transient simulations up to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mn>7</mml:mn> </mml:mrow> </mml:msup> </mml:math> s of continuous exposure are run with or without instantaneous recombination on the poloidal gaps. In the case of instantaneous recombination, the poloidal gaps act as a strong sink for hydrogen leading to a decrease in the monoblock inventory. The total desorption flux on the poloidal gap is greater than on the toroidal gap but remains orders of magnitude lower than the retro-desorbed flux at the top surface. For a monoblock thickness of 4 mm, the relative difference in the hydrogen inventory per unit thickness between the two cases is 500%. As the thickness of the monoblock increases, this difference decreases (55% at 14 mm). The monoblock’s response to baking is then studied at different baking temperatures. At 600 K, almost all the hydrogen content in the monoblock is removed after 15 days of baking. Assuming a non-instantaneous recombination on the tungsten surfaces would not have a major impact on the monoblock desorption for baking temperatures above 600 K. Hydrogen ; Materials science ; Tungsten ; Desorption ; Recombination ; Flux (metallurgy) ; Analytical Chemistry (journal) ; Physics ; Chemistry ; Physical chemistry Fusion materials and technologies ; Superconducting Materials and Applications ; Magnetic confinement fusion research