jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Shilpa Gaikwad | Sonali Kothari
Source: International Journal of Advanced Computer Science and Applications (article, 2022-01-01)
Field: Chemistry — Analytical Chemistry

Multi-Spectral Imaging for Fruits and Vegetables In the field of agriculture, fruit grading and veg-etable classification is an important and challenging task. The current fruit and vegetable classifications are done manually, which results in inconsistent performance. There is an influence of external surroundings on this manual classification. Sometimes getting an expert fruit or vegetable grader, is challenging and the performance of that person may become stagnant over some time. With the recent development in computer technology and multi-spectral camera system, it is possible to achieve an efficient fruit grading or vegetable classification system. In this manuscript, we summarize different automated fruit grading as well as vegetable classification systems, which are based on multi-spectral imaging. We have focused our analysis on four major areas such as varietal identification, fruit quality assessment, classification, and disease detection. From our analysis, we have found that the Partial Least Square Discriminant Analysis (PLS-DA) was most effective for identifying varieties of tomato seeds. For analyzing the quality of pomegranate fruits, the multiple linear regression model was the most optimal method. Multi-Layer Perceptron (MLP) classifier was the recommended method for classifying medicinal plant leaves. A Linear Discriminant Analysis (LDA) based classifier could accurately detect diseases in fruits and vegetables. Computer science ; Linear discriminant analysis ; Artificial intelligence ; Classifier (UML) ; Grading (engineering) ; Pattern recognition (psychology) ; Perceptron ; Multilayer perceptron ; Machine learning ; Artificial neural network Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Leaf Properties and Growth Measurement
Authors: Tao Du | Søren S. Sørensen | Theany To | Morten M. Smedskjær
Source: Journal of Applied Physics (article, 2022-05-02)
Field: Materials Science — Ceramics and Composites

Oxide glasses under pressure: Recent insights from experiments and simulations Deciphering the structure–property relations of densified oxide glasses is a problem of longstanding interest. For example, it is important for understanding the fracture mechanism under sharp contact loading as well as fabricating glasses with tunable physical characteristics. Recent advances in both experimental and simulation techniques have prompted research breakthroughs in understanding the response of glasses to high pressure. In this Perspective, we first briefly discuss the facilities for the high-pressure treatment of glasses, including in situ and ex situ investigations. The recent work on pressure-induced structural changes of archetypical oxide glass families (silicates, germanates, borates, aluminates, phosphates) is discussed and compared to the changes in macroscopic properties induced by densification, as densification treatment can be used to produce oxide glasses with improved hardness, stiffness, and toughness. We also discuss the new insights from atomistic simulations combined with topological analysis tools to unravel the densification mechanism of oxide glasses on the medium-range order length scale. Drawing on these recent studies, we clarify how densification treatment has proved to be an important tool to both understand the disordered nature of glasses and tune their physical properties, although many open questions and challenges remain that require further investigations. Materials science ; Oxide ; Metallurgy Glass properties and applications ; High-pressure geophysics and materials ; Luminescence Properties of Advanced Materials
Authors: Christos Liaskos | Ageliki Tsioliaridou | Κωνσταντίνος Γεωργόπουλος | Ioannis Morianos | Sotiris Ioannidis | Iosif Salem | Dionysios Manessis | Stefan Schmid | Dimitrios Tyrovolas | Sotiris A. Tegos | Prodromos‐Vasileios Mekikis | Panagiotis D. Diamantoulakis | Alexandros Pitilakis | Nikolaos V. Kantartzis | George K. Karagiannidis | Anna C. Tasolamprou | Odysseas Tsilipakos | Maria Kafesaki | Ian F. Akyildiz | Andreas Pitsillides | Maria Pateraki | Michael Vakalellis | Ilias Spais
Source: IEEE Access (article, 2022-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

XR-RF Imaging Enabled by Software-Defined Metasurfaces and Machine Learning: Foundational Vision, Technologies and Challenges We present a new approach to Extended Reality (XR), denoted as iCOPYWAVES, which seeks to offer naturally low-latency operation and cost effectiveness, overcoming the critical scalability issues faced by existing solutions. iCOPYWAVES is enabled by emerging PWEs, a recently proposed technology in wireless communications. Empowered by intelligent (meta)surfaces, PWEs transform the wave propagation phenomenon into a software-defined process. We leverage PWEs to: i) create, and then ii) selectively copy the scattered RF wavefront of an object from one location in space to another, where a machine learning module, accelerated by FPGAs, translates it to visual input for an XR headset using PWE-driven, RF imaging principles (XR-RF). This makes for an XR system whose operation is bounded in the physical-layer and, hence, has the prospects for minimal end-to-end latency. Over large distances, RF-to-fiber/fiber-to-RF is employed to provide intermediate connectivity. The paper provides a tutorial on the iCOPYWAVES system architecture and workflow. A proof-of-concept implementation via simulations is provided, demonstrating the reconstruction of challenging objects in iCOPYWAVES-produced computer graphics. Computer science ; Software-defined radio ; Software ; Radio frequency ; Artificial intelligence ; Human–computer interaction ; Computer vision ; Programming language ; Telecommunications Metamaterials and Metasurfaces Applications ; Antenna Design and Analysis ; Advanced Wireless Communication Technologies
Authors: Joel Davidsson | Rohit Babar | Danial Shafizadeh | Ivan G. Ivanov | Viktor Ivády | Rickard Armiento | Igor A. Abrikosov
Source: Nanophotonics (article, 2022-09-01)
Field: Materials Science — Materials Chemistry

Exhaustive characterization of modified Si vacancies in 4H‐SiC The negatively charged silicon vacancy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfenced> <mml:mrow> <mml:msubsup><mml:mrow><mml:mi>V</mml:mi></mml:mrow> <mml:mrow><mml:mi>S</mml:mi> <mml:mi>i</mml:mi></mml:mrow> <mml:mrow><mml:mo>-</mml:mo></mml:mrow> </mml:msubsup> </mml:mrow> </mml:mfenced> </mml:math> in silicon carbide is a well-studied point defect for quantum applications. At the same time, a closer inspection of ensemble photoluminescence and electron paramagnetic resonance measurements reveals an abundance of related but so far unidentified signals. In this study, we search for defects in 4H-SiC that explain the above magneto-optical signals in a defect database generated by automatic defect analysis and qualification (ADAQ) workflows. This search reveals only one class of atomic structures that exhibit silicon-vacancy-like properties in the data: a carbon antisite (C<sub>Si</sub>) within sub-nanometer distances from the silicon vacancy only slightly alters the latter without affecting the charge or spin state. Such a perturbation is energetically bound. We consider the formation of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup><mml:mrow><mml:mi>V</mml:mi></mml:mrow> <mml:mrow><mml:mi>S</mml:mi> <mml:mi>i</mml:mi></mml:mrow> <mml:mrow><mml:mo>-</mml:mo></mml:mrow> </mml:msubsup> <mml:mo>+</mml:mo> <mml:msub><mml:mrow><mml:mi>C</mml:mi></mml:mrow> <mml:mrow><mml:mi>S</mml:mi> <mml:mi>i</mml:mi></mml:mrow> </mml:msub> </mml:math> up to 2 nm distance and report their zero phonon lines and zero field splitting values. In addition, we perform high-resolution photoluminescence experiments in the silicon vacancy region and find an abundance of lines. Comparing our computational and experimental results, several configurations show great agreement. Our work demonstrates the effectiveness of a database with high-throughput results in the search for defects in quantum applications. Vacancy defect ; Photoluminescence ; Silicon ; Materials science ; Silicon carbide ; Electron paramagnetic resonance ; Crystallographic defect ; Condensed matter physics ; Nanotechnology ; Molecular physics ; Optoelectronics ; Physics ; Nuclear magnetic resonance Diamond and Carbon-based Materials Research ; Silicon Carbide Semiconductor Technologies ; Semiconductor materials and devices
Authors: Philipp Schleich | Jakob S. Kottmann | Alán Aspuru‐Guzik
Source: Physical Chemistry Chemical Physics (article, 2022-01-01)
Field: Chemistry — Spectroscopy

Improving the accuracy of the variational quantum eigensolver for molecular systems by the explicitly-correlated perturbative [2]<sub>R12</sub><b>-</b>correction We provide an integration of the universal, perturbative explicitly correlated [2]<sub>R12</sub>-correction in the context of the Variational Quantum Eigensolver (VQE). This approach is able to increase the accuracy of the underlying reference method significantly while requiring no additional quantum resources. The proposed approach only requires knowledge of the one- and two-particle reduced density matrices (RDMs) of the reference wavefunction; these can be measured after having reached convergence in the VQE. This computation comes at a cost that scales as the sixth power of the number of electrons. We explore the performance of the VQE + [2]<sub>R12</sub> approach using both conventional Gaussian basis sets and our recently proposed directly determined pair-natural orbitals obtained by multiresolution analysis (MRA-PNOs). Both Gaussian orbital and PNOs are investigated as a potential set of complementary basis functions in the computation of [2]<sub>R12</sub>. In particular the combination of MRA-PNOs with [2]<sub>R12</sub> has turned out to be very promising - persistently throughout our data, this allowed very accurate simulations at a quantum cost of a minimal basis set. Additionally, we found that the deployment of PNOs as complementary basis can greatly reduce the number of complementary basis functions that enter the computation of the correction at a complexity. Wave function ; Gaussian ; Atomic orbital ; Computation ; Basis (linear algebra) ; Basis set ; Computer science ; Context (archaeology) ; Quantum computer ; Quantum ; Statistical physics ; Applied mathematics ; Physics ; Algorithm ; Mathematics ; Quantum mechanics ; Electron ; Density functional theory Molecular spectroscopy and chirality ; Spectroscopy and Quantum Chemical Studies ; Quantum Computing Algorithms and Architecture
Authors: Ondrej Dyck | Sinchul Yeom | Sarah Dillender | Andrew R. Lupini | Mina Yoon | Stephen Jesse
Source: Carbon (article, 2022-09-07)
Field: Materials Science — Materials Chemistry

The role of temperature on defect diffusion and nanoscale patterning in graphene Graphene ; Materials science ; Nanotechnology ; Atomic units ; Graphite ; Coalescence (physics) ; Chemical physics ; Nanoscopic scale ; Scanning transmission electron microscopy ; Fabrication ; Graphene nanoribbons ; Transmission electron microscopy ; Chemistry ; Physics Graphene research and applications ; Advanced Electron Microscopy Techniques and Applications ; Electron and X-Ray Spectroscopy Techniques
Authors: Ting Zhang | Yuyang Liu | Zhuoping Dai | Lihan Cui | Hongze Lin | Zejian Li | Kaihua Wu | Guangyu Liu
Source: Sensors (article, 2022-02-06)
Field: Chemistry — Analytical Chemistry

Quantitative Detection of Extra Virgin Olive Oil Adulteration, as Opposed to Peanut and Soybean Oil, Employing LED-Induced Fluorescence Spectroscopy As it is high in value, extra virgin olive oil (EVOO) is frequently blended with inferior vegetable oils. This study presents an optical method for determining the adulteration level of EVOO with soybean oil as well as peanut oil using LED-induced fluorescence spectroscopy. Eight LEDs with central wavelengths from ultra-violet (UV) to blue are tested to induce the fluorescence spectra of EVOO, peanut oil, and soybean oil, and the UV LED of 372 nm is selected for further detection. Samples are prepared by mixing olive oil with different volume fractions of peanut or soybean oil, and their fluorescence spectra are collected. Different pre-processing and regression methods are utilized to build the prediction model, and good linearity is obtained between the predicted and actual adulteration concentration. This result, accompanied by the non-destruction and no pre-treatment characteristics, proves that it is feasible to use LED-induced fluorescence spectroscopy as a way to investigate the EVOO adulteration level, and paves the way for building a hand-hold device that can be applied to real market conditions in the future. Olive oil ; Peanut oil ; Fluorescence spectroscopy ; Soybean oil ; Fluorescence ; Spectroscopy ; Ultraviolet visible spectroscopy ; Chemistry ; Mixing (physics) ; Palm oil ; Light-emitting diode ; Food science ; Vegetable oil ; Chromatography ; Materials science ; Analytical Chemistry (journal) ; Optoelectronics ; Optics ; Physics Spectroscopy and Chemometric Analyses ; Edible Oils Quality and Analysis ; Advanced Chemical Sensor Technologies
Authors: Behnam Ranjbar | Ali Darvishi | Rahman Dashti | Hamid Reza Shaker
Source: Energies (article, 2022-10-31)
Field: Materials Science — Materials Chemistry

A Survey of Diagnostic and Condition Monitoring of Metal Oxide Surge Arrester in the Power Distribution Network Metal oxide surge arresters (MOSAs) are a popular solution for dealing with overvoltages due to lightning and switching in power distribution networks. As a result, a MOSA’s performance and longevity have a significant impact on the quality of energy and the frequency of outages. A MOSA performance is determined by several elements such as leakage current, partial discharge, and thermal image measured in various ways. In this study, different techniques for diagnostic and condition monitoring of MOSAs are discussed, and each method’s advantages and disadvantages are investigated. Additionally, the results of practical tests on two 20 kV healthy and degraded MOSAs are investigated and compared. Surge arrester ; Lightning arrester ; Electrical engineering ; Surge ; Power quality ; Power (physics) ; Engineering ; Power network ; Reliability engineering ; Electronic engineering ; Automotive engineering ; Voltage ; Electric power system ; Physics High voltage insulation and dielectric phenomena ; Lightning and Electromagnetic Phenomena ; Electrical Fault Detection and Protection
Authors: Jonathan Z. Lu | Ziyan Zhu | Mattia Angeli | Daniel T. Larson | Efthimios Kaxiras
Source: Physical review. B./Physical review. B (article, 2022-10-10)
Field: Materials Science — Materials Chemistry

Low-energy moiré phonons in twisted bilayer van der Waals heterostructures We develop a low-energy continuum model for phonons in twisted moir\'e bilayers, based on a configuration space approach. In this approach, interatomic force constants are obtained from density functional theory (DFT) calculations of untwisted bilayers with various in-plane shifts. This allows for efficient computation of phonon properties for any small twist angle, while maintaining DFT-level accuracy. Based on this framework, we show how the low-energy phonon modes, including interlayer shearing and layer breathing modes, vary with the twist angle. As the twist angle decreases, the frequencies of the low-energy modes are reordered and the atomic displacement fields corresponding to phonon eigenmodes break translational symmetry, developing periodicity on the moir\'e length scale. We demonstrate the capabilities of our model by calculating the phonon properties of three specific structures: Bilayer graphene, bilayer molybdenum disulfide $({\mathrm{MoS}}_{2})$, and molybdenum diselenide-tungsten diselenide $({\mathrm{MoSe}}_{2}\text{\ensuremath{-}}{\mathrm{WSe}}_{2})$. Phonon ; Tungsten diselenide ; Translational symmetry ; Condensed matter physics ; Materials science ; van der Waals force ; Bilayer ; Density functional theory ; Bilayer graphene ; Molecular physics ; Graphene ; Physics ; Chemistry ; Nanotechnology ; Quantum mechanics ; Transition metal ; Molecule 2D Materials and Applications ; Boron and Carbon Nanomaterials Research ; Thermal properties of materials
Authors: Adam J. Simpkin | Jens M. H. Thomas | Ronan M. Keegan | Daniel J. Rigden
Source: Acta Crystallographica Section D Structural Biology (article, 2022-04-26)
Field: Materials Science — Materials Chemistry

<i>MrParse</i> : finding homologues in the PDB and the EBI AlphaFold database for molecular replacement and more Crystallographers have an array of search-model options for structure solution by molecular replacement (MR). The well established options of homologous experimental structures and regular secondary-structure elements or motifs are increasingly supplemented by computational modelling. Such modelling may be carried out locally or may use pre-calculated predictions retrieved from databases such as the EBI AlphaFold database. MrParse is a new pipeline to help to streamline the decision process in MR by consolidating bioinformatic predictions in one place. When reflection data are provided, MrParse can rank any experimental homologues found using eLLG, which indicates the likelihood that a given search model will work in MR. Inbuilt displays of predicted secondary structure, coiled-coil and transmembrane regions further inform the choice of MR protocol. MrParse can also identify and rank homologues in the EBI AlphaFold database, a function that will also interest other structural biologists and bioinformaticians. Computer science ; Pipeline (software) ; Database ; Rank (graph theory) ; Process (computing) ; Data mining ; Function (biology) ; Computational biology ; Information retrieval ; Bioinformatics ; Biology ; Mathematics ; Programming language ; Genetics Enzyme Structure and Function ; Protein Structure and Dynamics ; RNA and protein synthesis mechanisms
Authors: Fan Yang | Sensong An | Mikhail Y. Shalaginov | Hualiang Zhang | Juejun Hu | Tian Gu
Source: Chinese Optics Letters (article, 2022-10-21)
Field: Materials Science — Surfaces, Coatings and Films

Understanding wide field-of-view flat lenses: an analytical solution [Invited] Wide field-of-view (FOV) optics are widely used in various imaging, display, and sensing applications. Conventional wide FOV optics rely on complicated lens assembly comprising multiple elements to suppress coma and other Seidel aberrations. The emergence of flat optics exemplified by metasurfaces and diffractive optical elements (DOEs) offers a promising route to expand the FOV without escalating complexity of optical systems. To date, design of large FOV flat lenses has been relying upon iterative numerical optimization. Here, we derive, for the first time, to the best of our knowledge, an analytical solution to enable computationally efficient design of flat lenses with an ultra-wide FOV approaching 180. This analytical theory further provides critical insights into working principles and otherwise non-intuitive design trade-offs of wide FOV optics. Optics ; Lens (geology) ; Coma (optics) ; Field of view ; Computer science ; Geometrical optics ; Physics ; Field (mathematics) Optical Coatings and Gratings ; Advanced optical system design ; Optical Wireless Communication Technologies
Authors: Kaixu Zhang | Hongzhe Jiang | Haicheng Zhang | Zequn Zhao | Yingjie Yang | Shudan Guo | Wei Wang
Source: Agriculture (article, 2022-03-30)
Field: Chemistry — Analytical Chemistry

Online Detection and Classification of Moldy Core Apples by Vis-NIR Transmittance Spectroscopy Apple moldy core disease is a common internal fungal disease. The online detection and classification of apple moldy core plays a vital role in apple postharvest processing. In this paper, an online non-destructive detection system for apple moldy core disease was developed using near-infrared transmittance spectroscopy in spectral range of 600–1100 nm. A total of 120 apple samples were selected and randomly divided into a training set and a test set based on the ratio of 2:1. First, basic parameters for detection of apples with moldy core were determined through detection experiments of samples in a stationary state. Due to the random distribution of the diseased tissue inside diseased apples, stationary detection cannot accurately identify the diseased tissue. To solve this problem, the spectra of apples in motion state transmitted forward by the transmission line were acquired. Three placement orientations of the apple in the carrying fruit cup were tested to explore the influence of fruit orientation on spectral characteristics and prediction. According to the performance of the model, the optimal preprocessing method and modeling method were determined (fixed orientation model and arbitrary orientation model). SPA was used to select the characteristic wavelengths to further improve the online detection speed. The overall results showed that the multi-spectra model using mean spectra of three orientations was the best. The prediction accuracies of multi-spectra model using SPA for three orientations were 96.7%, 97.5% and 97.5% respectively. As a conclusion, the arbitrary orientation model was beneficial to improve the online detection of apple moldy core disease. Preprocessor ; Transmittance ; Orientation (vector space) ; Artificial intelligence ; Mathematics ; Biological system ; Computer science ; Pattern recognition (psychology) ; Optics ; Biology ; Physics ; Geometry Spectroscopy and Chemometric Analyses ; Essential Oils and Antimicrobial Activity ; Spectroscopy Techniques in Biomedical and Chemical Research