jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Kapil Gupta
Source: Advances in Science and Technology – Research Journal (article, 2021-08-18)
Field: Materials Science — Materials Chemistry

Intelligent Machining of Shape Memory Alloys Shape memory alloys are important biomaterials but difficult-to-machine (DTM). Their machining needs to be done using intelligent techniques to obtain a better machinability. Hybrid optimization is one of such techniques which can perform modeling and optimization of machining parameters for the best values of machinability indicators. Wire electric discharge machining (WEDM) of shape memory alloy has been found as a prominent alternate to the conventional machining techniques; however it needs the assistance of intelligent techniques to machine such materials to obtain the optimum values of machinability indicators. In this paper, WEDM of shape memory alloy Ni 55.8 Ti was reported. WEDM was carried out by varying four process parameters i.e. servo voltage SV, pulse-on time P on , pulse-off time P off , and wire feed rate WF using Taguchi L 16 robust design of experiment technique. A hybrid optimization technique TOPSIS-Fuzzy-PSO has been successfully used to optimize these parameters (SV-50V; P on -1s; P off -17 s; WF-4 m/min) for the best possible values of material removal rate (MRR) -0.049 g/min, maximum roughness -11.45 m, and recast layer -22.10 m simultaneously. Machining ; Materials science ; Shape-memory alloy ; Mechanical engineering ; Engineering drawing ; Computer science ; Metallurgy ; Manufacturing engineering ; Engineering Shape Memory Alloy Transformations ; Manufacturing Process and Optimization ; Laser and Thermal Forming Techniques
Authors: Anderson Edson da Silva | Ismael Nogueira Rabelo de Melo | Ivete Peixoto Pinheiro | Leonardo Roberto da Silva
Source: Materials Research (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

Influence of Niobium Addition on Microstructure and Machinability of High Chromium Cast Iron High Chromium Cast Iron (HCCI) is mostly utilised in environments under severe abrasion and corrosion wear conditions, and research on this material with added niobium obtained positive results regarding wear resistance. The casting process has surface finish and dimensional accuracy limitations compared to machining processes. There are too few studies about HCCI machinability and no one about HCCI with niobium additions. HCCI machinability studies may allow new applications for this material when excellent surface finish and high dimensional accuracy are required. This study analyses the influence of 0.5% Nb addition on the microstructure and machinability of a HCCI alloy with 25.6% Cr and 3.2% C. The samples were heat treated and subsequently machined in dry cutting conditions. Annealing was used to facilitate the pre-machining of the samples, which were later quenched and tempered. Microstructure and hardness were analysed at each stage of the heat treatment. The material was machined after tempered using polycrystalline cubic boron nitride (pcBN) tools. The alloys solidified in the hypereutectic condition. The addition of niobium reduced the hardness and carbide volumetric fraction, increased the service life of the cutting tools in all tests, provided better surface finishing and modified the wear mechanisms. Machinability ; Materials science ; Metallurgy ; Microstructure ; Niobium ; Machining ; Carbide ; Cast iron ; Ingot ; Niobium carbide ; Inconel ; Alloy Metal Alloys Wear and Properties ; Advanced materials and composites ; Metal and Thin Film Mechanics
Authors: Claudia Richert | Yijuan Wu | Murilo P. Hablitzel | Erica T. Lilleodden | N. Huber
Source: MRS Advances (article, 2021-07-14)
Field: Materials Science — Materials Chemistry

Image segmentation and analysis for densification mapping of nanoporous gold after nanoindentation Abstract Segmentation of scanning electron microscopy (SEM) images of focused ion beam (FIB) cross-sections through indented regions in nanoporous gold (np-Au) is carried out. A key challenge for image analysis of open porous materials is the appropriate binarization of the pore and gold ligament regions while excluding material lying below the cross-sectional plane. Here, a manual approach to thresholding is compared to global and local approaches. The global thresholding resulted in excessive deviations from the nominal solid fraction, due to a strong gray-scale gradient caused by the tilt angle during imaging and material shadowing. In contrast, the local thresholding approach delivered local solid fractions that were free of global gradients, and delivered a quality comparable to the manual segmentation. The extracted densification profiles vertically below the indenter as well as parallel to the surface showed an exponential-type decay from the indenter tip towards the nominal value of 1 far from the indenter. Graphic abstract Materials science ; Thresholding ; Nanoindentation ; Nanoporous ; Segmentation ; Focused ion beam ; Scanning electron microscope ; Artificial intelligence ; Composite material ; Nanotechnology ; Image (mathematics) ; Ion ; Computer science Nanoporous metals and alloys ; Anodic Oxide Films and Nanostructures ; Electrodeposition and Electroless Coatings
Authors: Lukas S. Stelzl | Lisa M. Pietrek | Andrea Holla | Javier Oroz | Mateusz Sikora | Jürgen Köfinger | Benjamin Schuler | Markus Zweckstetter | Gerhard Hummer
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2021-11-24)
Field: Chemistry — Spectroscopy

Global Structure of the Intrinsically Disordered Protein Tau Emerges from its Local Structure Abstract The paradigmatic disordered protein tau plays an important role in neuronal function and neurodegenerative diseases. To disentangle the factors controlling the balance between functional and disease-associated conformational states, we build a structural ensemble of the tau K18 fragment containing the four pseudorepeat domains involved in both microtubule binding and amyloid fibril formation. We assemble 129-residue-long tau K18 chains at atomic resolution from an extensive fragment library constructed with molecular dynamics simulations. We introduce a reweighted hierarchical chain growth (RHCG) algorithm that integrates experimental data reporting on the local structure into the assembly process in a systematic manner. By combining Bayesian ensemble refinement with importance sampling, we obtain well-defined ensembles and overcome the problem of exponentially varying weights in the integrative modeling of long-chain polymeric molecules. The resulting tau K18 ensembles capture nuclear magnetic resonance (NMR) chemical shift and J-coupling measurements. Without further fitting, we achieve excellent agreement with measurements of NMR residual dipolar couplings. The good agreement with experimental measures of global structures such as singlemolecule Förster resonance energy transfer (FRET) efficiencies is improved further by ensemble refinement. By comparing wild-type and mutant ensembles, we show that pathogenic single-point P301 mutations shift the population from the turn-like conformations of the functional microtubule-bound state to the extended conformations of disease-associated tau fibrils. RHCG thus provides us with an atomically resolved view of the population equilibrium between functional and aggregation-prone states of tau K18, and demonstrates that global structural characteristics of this intrinsically disordered protein emerge from its local structure. Intrinsically disordered proteins ; Conformational ensembles ; Population ; Molecular dynamics ; Chemistry ; Residual dipolar coupling ; Chemical physics ; Physics ; Biological system ; Nuclear magnetic resonance spectroscopy ; Computational chemistry ; Nuclear magnetic resonance ; Stereochemistry ; Biology Advanced NMR Techniques and Applications ; Alzheimer's disease research and treatments ; Advanced Neuroimaging Techniques and Applications
Authors: Peter W. Stokes | Ronald D. White | L. Campbell | M. J. Brunger
Source: The Journal of Chemical Physics (article, 2021-08-28)
Field: Chemistry — Spectroscopy

Toward a complete and comprehensive cross section database for electron scattering from NO using machine learning We review experimental and theoretical cross sections for electron scattering in nitric oxide (NO) and form a comprehensive set of plausible cross sections. To assess the accuracy and self-consistency of our set, we also review electron swarm transport coefficients in pure NO and admixtures of NO in Ar, for which we perform a multi-term Boltzmann equation analysis. We address observed discrepancies with these experimental measurements by training an artificial neural network to solve the inverse problem of unfolding the underlying electron-NO cross sections while using our initial cross section set as a base for this refinement. In this way, we refine a suitable quasielastic momentum transfer cross section, a dissociative electron attachment cross section, and a neutral dissociation cross section. We confirm that the resulting refined cross section set has an improved agreement with the experimental swarm data over that achieved with our initial set. We also use our refined database to calculate electron transport coefficients in NO, across a large range of density-reduced electric fields from 0.003 to 10 000 Td. Section (typography) ; Cross section (physics) ; Scattering ; Electron ; Computer science ; Database ; Physics ; Nuclear physics ; Optics ; Quantum mechanics Mass Spectrometry Techniques and Applications ; Electron and X-Ray Spectroscopy Techniques ; Plasma Applications and Diagnostics
Authors: Karl B. Hoffmann | Ivo F. Sbalzarini
Source: Physical review. E (article, 2021-01-05)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Robustness of topological defects in discrete domains Topological defects are singular points in vector fields, important in applications ranging from fingerprint detection to liquid crystals to biomedical imaging. In discretized vector fields, topological defects and their topological charge are identified by finite differences or finite-step paths around the tentative defect. As the topological charge is (half) integer, it cannot depend continuously on each input vector in a discrete domain. Instead, it switches discontinuously when vectors change beyond a certain amount, making the analysis of topological defects error prone in noisy data. We improve existing methods for the identification of topological defects by proposing a robustness measure for (i) the location of a defect, (ii) the existence of topological defects and the total topological charge within a given area, (iii) the annihilation of a defect pair, and (iv) the formation of a defect pair. Based on the proposed robustness measure, we show that topological defects in discrete domains can be identified with optimal trade-off between localization precision and robustness. The proposed robustness measure enables uncertainty quantification for topological defects in noisy discretized nematic fields (orientation fields) and polar fields (vector fields). Robustness (evolution) ; Topological quantum number ; Topology (electrical circuits) ; Topological defect ; Physics ; Algorithm ; Mathematics ; Quantum mechanics ; Combinatorics Liquid Crystal Research Advancements ; Topological and Geometric Data Analysis ; Advanced Fluorescence Microscopy Techniques
Authors: Jianfang Xue | Ling Zhu | Yanan Jiao | Guan Yanliang
Source: Cellular and Molecular Biology (article, 2021-11-25)
Field: Chemistry — Organic Chemistry

The effect of Chaihu-shugan-san on cytotoxicity induction and PDGF gene expression in cervical cancer cell line HeLa in the presence of paclitaxel +cisplatin Chaihu-shugan-san, as a traditional Chinese herbal formula, is composed of seven different herbs. This medicine can treat cancer due to its antioxidant compounds. In this study, the effect of Chaihu-shugan-san was considered on cytotoxicity induction and PDGF gene expression in cervical cancer cell line HeLa at different concentrations and at different times, by the MTT method. Paclitaxel + cisplatin were used as a control in this study. The expression of the PDGF gene was quantitatively evaluated in treated cells by real-time PCR, and a generalized linear model was used to evaluate the effect of the medicine, and Duncan's multiple range tests were used to evaluate the data. The results of the MTT test showed that Chaihu-shugan-san had antitumor properties in different concentrations, but there was a significant difference between this medicine and paclitaxel +cisplatin. Also, examination of gene expression showed that this medicine reduced the expression of the PDGF gene in the HeLa cancer cell line (P ? 0.04). Therefore, Chaihu-shugan-san could be suggested as an effective factor in preventing the growth of cervical cancer cells and controlling angiogenic factors that play an important role in the metastasis of cancerous tumors. HeLa ; Cisplatin ; Paclitaxel ; Cytotoxicity ; MTT assay ; Cell culture ; Cancer research ; Cervical cancer ; Medicine ; Cancer ; Pharmacology ; Platelet-derived growth factor receptor ; Traditional medicine ; Molecular biology ; Biology ; Chemotherapy ; Growth factor ; Internal medicine ; In vitro ; Biochemistry Synthesis and biological activity ; Molecular Biology Techniques and Applications ; Cancer, Lipids, and Metabolism
Authors: Sachithri Munasinghe | Seneviratnege Somaratne | S. R. Weerakoon | Chandani Ranasinghe
Source: Journal of Genetic Engineering and Biotechnology (article, 2021-09-03)
Field: Chemistry — Organic Chemistry

Sustainable utilization of Gyrinops walla Gaetner: in vitro production of sesquiterpenes by chemical and biological elicitation The findings of the study led to the conclusion of the possibility of induction of production of sesquiterpenes through elicitation of G. walla calli and cell suspension in an in vitro system for sustainable utilization and conservation endeavours. Callus ; Trichoderma viride ; Aspergillus niger ; Lasiodiplodia theobromae ; Trichoderma harzianum ; Horticulture ; Methyl jasmonate ; Botany ; Biology ; Traditional medicine ; Food science ; Chemistry ; Biological pest control ; Biochemistry ; Medicine Wood and Agarwood Research ; Plant Pathogens and Fungal Diseases ; Forest Ecology and Biodiversity Studies
Authors: Zhuyun Xiao | Chelsea Lai | Ruoda Zheng | Maite Goiriena‐Goikoetxea | Nobumichi Tamura | Cornelio Torres Juarez | C. Perry | Hanuman Singh | Jeffrey Bokor | Gregory P. Carman | Rob N. Candler
Source: Applied Physics Letters (article, 2021-05-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Localized strain profile in surface electrode array for programmable composite multiferroic devices We investigate localized in-plane strains on the microscale, induced by arrays of biased surface electrodes patterned on piezoelectrics. Particular focus is given to the influence that adjacent electrode pairs have on one another to study the impact of densely packed electrode arrays. We present a series of X-ray microdiffraction studies to reveal the spatially resolved micrometer-scale strain distribution. The strain maps with micrometer-scale resolution highlight how the local strain profile in square regions up to 250 × 250 μm2 in size is affected by the surface electrodes that are patterned on ferroelectric single-crystal [Pb(Mg1/3Nb2/3)O3]x-[PbTiO3]1−x. The experimental measurements and simulation results show the influence of electrode pair distance, positioning of the electrode pair, including the angle of placement, and neighboring electrode pair arrangements on the strength and direction of the regional strain. Our findings are relevant to the development of microarchitected strain-mediated multiferroic devices. The electrode arrays could provide array-addressable localized strain control for applications including straintronic memory, probabilistic computing platforms, microwave devices, and magnetic-activated cell sorting platforms. Materials science ; Electrode ; Micrometer ; Microscale chemistry ; Ferroelectricity ; Electrode array ; Optoelectronics ; Nanotechnology ; Optics ; Dielectric Multiferroics and related materials ; Ferroelectric and Piezoelectric Materials ; Acoustic Wave Resonator Technologies
Authors: Mirza Imran Tariq | Majad Mansoor | Adeel Feroz Mirza | Nouman Mujeeb Khan | Muhammad Hamza Zafar | Abbas Z. Kouzani | M. A. Parvez Mahmud
Source: Electronics (article, 2021-11-18)
Field: Materials Science — Materials Chemistry

Optimal Control of Centralized Thermoelectric Generation System under Nonuniform Temperature Distribution Using Barnacles Mating Optimization Algorithm The need for renewable energy resources is ever-increasing due to the concern for environmental issues associated with fossil fuels. Low-cost high-power-density manufacturing techniques for the thermoelectric generators (TEG) have added to the technoeconomic feasibility of the TEG systems as an effective power generation system in heat recovery, cooling, electricity, and engine-efficiency applications. The environment-dependent factors such as the nonuniform distribution of heat, damage to the heat-transfer coating between sinks and sources, and mechanical faults create nonuniform current generation and impedance mismatch causing power loss. As a solution to this nonlinear multisolution problem, an improved MPPT control is presented, which utilizes the improvised barnacle mating optimization (BMO). The case studies are formulated to gauge the performance of the proposed BMP MPPT control under nonuniform temperature distribution. The results are compared to the grey wolf optimization (GWO), particle swarm optimization (PSO), and cuckoo search (CS) algorithm. Faster global maximum power point tracking (GMPP) within 381 ms, higher power tracking efficiency of up to 99.93%, and least oscillation ≈0.8 W are achieved by the proposed BMO with the highest energy harvest on average. The statistical analysis further solidifies the better performance of the proposed controller with the least root mean square error (RMSE), RE, and highest SR. Particle swarm optimization ; Control theory (sociology) ; Electricity generation ; Cuckoo search ; Thermoelectric generator ; Maximum power point tracking ; Controller (irrigation) ; Mean squared error ; Computer science ; Power (physics) ; Automotive engineering ; Environmental science ; Materials science ; Engineering ; Algorithm ; Mathematics ; Thermoelectric effect ; Electrical engineering ; Voltage ; Physics ; Statistics ; Control (management) Advanced Thermoelectric Materials and Devices ; Innovative Energy Harvesting Technologies ; Microgrid Control and Optimization
Authors: Takumi Ishikawa | Sumito NAGASAWA
Source: Intelligent Service Robotics (article, 2021-04-22)
Field: Materials Science — Materials Chemistry

SMA micro-hand implemented in small robot for generating gestures The online version supplementary material available at 10.1007/s11370-021-00364-9. Gesture ; Computer science ; Robot ; SMA* ; Actuator ; Shape-memory alloy ; Artificial intelligence ; Simulation ; Algorithm Shape Memory Alloy Transformations ; Robot Manipulation and Learning ; Hand Gesture Recognition Systems
Authors: Abdullah Beyaz | Dilara Gerdan Koç
Source: Tarım Bilimleri Dergisi (article, 2021-01-14)
Field: Chemistry — Analytical Chemistry

Meta-learning Based Prediction of Different Corn Cultivars from Colour Feature Extraction with Image Processing Technique Image analysis techniques are developing as applicable to the approaches of quantitative analysis, which is aimed to determine cultivar grains. Additionally, corn (Zea mays) grain processing companies evaluate the quality of kernels to determine the price of these cultivars. Because of this reason, in the study, a computer image analysis technique was applied on three corn cultivars. These were Zea mays L. indentata, Zea mays L. saccharata and a hybrid corn (Yellow sweet corn). These cultivars are commercially important as dry grains in Turkey. In the study, the grain color values were tested in the cultivars from Turkey's collection. One hundred samples were used for each corn cultivar, and 300 corn grains in total were used for evaluations. Each of nine color parameters (Rmin, Rmean, Rmax, Gmin, Gmean, Gmax, Bmin, Bmean, Bmax) which were obtained from original RGB color channels with maximum and minimum values was evaluated from the digital images of three different corn cultivar grains. The values were analyzed with the help of the Multilayer Perceptron (MLP), Decision Tree (DT), Gradient Boost Decision Tree (GBDT) and Random Forest (RF) algorithms by using the Knime Analytics Platform. The majority voting method was applied to MLP and DT for prediction fusion. All algorithms were run with a 10-fold cross-validation method. The success of prediction accuracy was found as 99% for RF and GBDT, 97.66% for MLP, 96.66% DT and 97.40% for Majority Voting (MAVL). The MAVL method increased the accuracy of DT while decreasing the accuracy of MLP partly for the fusion of MLP and DT. Cultivar ; Zea mays ; Multilayer perceptron ; Decision tree ; Mathematics ; Artificial intelligence ; RGB color model ; Random forest ; Agronomy ; Horticulture ; Computer science ; Biology ; Artificial neural network Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Advanced Chemical Sensor Technologies
Authors: Leixin Miao | Adrian Chmielewski | Debangshu Mukherjee | Nasim Alem
Source: Journal of Visualized Experiments (article, 2021-07-03)
Field: Materials Science — Surfaces, Coatings and Films

Picometer-Precision Atomic Position Tracking through Electron Microscopy The modern aberration-corrected scanning transmission electron microscopes (AC-STEM) have successfully achieved direct visualization of atomic columns with sub-angstrom resolution. With this significant progress, advanced image quantification and analysis are still at the early stages. In this work, we present the complete pathway for the metrology of atomic resolution scanning transmission electron microscopy (STEM) images. This includes (1) tips for acquiring high-quality STEM images; (2) denoising and drift-correction for enhancing measurement accuracy; (3) obtaining initial atomic positions; (4) indexing the atoms based on unit cell vectors; (5) quantifying the atom column positions with either 2D-Gaussian single peak fitting or (6) multi-peak fitting routines for slightly overlapping atomic columns; (7) quantification of lattice distortion/strain within the crystal structures or at the defects/interfaces where the lattice periodicity is disrupted; and (8) some common methods to visualize and present the analysis. Furthermore, a simple self-developed free MATLAB app (EASY-STEM) with a graphical user interface (GUI) will be presented. The GUI can assist in the analysis of STEM images without the need for writing dedicated analysis code or software. The advanced data analysis methods presented here can be applied for the local quantification of defect relaxations, local structural distortions, local phase transformations, and non-centrosymmetry in a wide range of materials. Scanning transmission electron microscopy ; Electron tomography ; Visualization ; Metrology ; Computer science ; Lattice (music) ; High-resolution transmission electron microscopy ; Graphical user interface ; Optics ; Materials science ; Physics ; Transmission electron microscopy ; Artificial intelligence Electron and X-Ray Spectroscopy Techniques ; Advanced Electron Microscopy Techniques and Applications ; Advanced Materials Characterization Techniques