jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Chang Su | Yongli Zhang | Xinle Yang | Jun Tu
Source: IEEE Access (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Numerical Simulation of the Temperature Field of Coal Subjected to Microwave Directional Heating Microwave directional heating can rapidly increase the temperature of coal and promote the desorption of coalbed methane. The temperature field of coal subjected to microwave directional heating was simulated by using COMSOL software. By coupling the energy conservation equation for an electromagnetic field with the heat conduction equation for solids, a heat conduction equation for the microwave directional heating of coal was established. The effects of the microwave heating time, power, frequency, incident distance and cross-sectional area of the waveguide on the temperature field of coal were studied via simulation. The results revealed that the increasing rate of temperature was high in the early stages of microwave heating. Moreover, higher microwave power corresponded to a higher coal sample temperature, a larger temperature gradient for the coal sample, and less energy being required to achieve the desired coal sample temperature. Additionally, it was found that there is an optimal microwave frequency that maximises the temperature of the coal sample. A larger microwave incident distance resulted in a lower average coal sample temperature. The waveguide was also found to have an optimal cross-sectional area that maximises the maximum temperature of the coal sample. Coal ; Microwave ; Materials science ; Temperature gradient ; Energy value of coal ; Thermal conduction ; Dielectric heating ; Electromagnetic field ; Mechanics ; Chemistry ; Composite material ; Physics ; Meteorology Microwave-Assisted Synthesis and Applications ; Coal Properties and Utilization ; Coal and Coke Industries Research
Authors: Linsheng Huang | Hansu Zhang | Chao Ruan | Wenjiang Huang | Tingguang Hu | Jinling Zhao
Source: International journal of agricultural and biological engineering (article, 2020-01-01)
Field: Chemistry — Analytical Chemistry

Detection of scab in wheat ears using in situ hyperspectral data and support vector machine optimized by genetic algorithm A new method was proposed to extract sensitive features and to construct a monitoring model for wheat scab based on in situ hyperspectral data of wheat ears to achieve effective prevention and control and provide theoretical support for its large-scale monitoring. Eight sensitive features were selected through correlation analysis and wavelet transform. These features were as follows: three original bands of 350-400 nm, 500-600 nm, and 720-1000 nm; three vegetation indices of modified simple ratio (MSR), normalized difference vegetation index, and structural independent pigment index; and two wavelet features of WF01 and WF02. By combining the selected sensitive features with support vector machine (SVM) and SVM optimized by genetic algorithm (GASVM), a total of 16 monitoring models were built, and the monitoring accuracies of the two types of models were compared. The ability of the monitoring models built by GASVM to identify scab was better than that of SVM algorithm under the same characteristic variables. Among the 16 models, MSR combined with GASVM had an overall accuracy of 75% and a Kappa coefficient of 0.47. GASVM can be used to monitor wheat scab and its application can improve the accuracy of disease monitoring. Keywords: wheat scab, hyperspectral data, correlation analysis, genetic algorithm, wavelet transform, support vector machine DOI: 10.25165/j.ijabe.20201302.5331 Citation: Huang L S, Zhang H S, Ruan C, Huang W J, Hu T G, Zhao J L. Detection of scab in wheat ears using in situ hyperspectral data and support vector machine optimized by genetic algorithm. Int J Agric & Biol Eng, 2020; 13(2): 182–188. Hyperspectral imaging ; Support vector machine ; Correlation coefficient ; Mathematics ; Artificial intelligence ; Pattern recognition (psychology) ; Wavelet ; Algorithm ; Computer science ; Statistics Spectroscopy and Chemometric Analyses
Authors: Kajetan Koperwas | Karolina Adrjanowicz | A. Grzybowski | Marian Paluch
Source: Scientific Reports (article, 2020-01-14)
Field: Materials Science — Materials Chemistry

The role of the dipole moment orientations in the crystallization tendency of the van der Waals liquids – molecular dynamics simulations Computer simulations of model systems play a remarkable role in the contemporary studies of structural, dynamic and thermodynamic properties of supercooled liquids. However, the commonly employed model systems, i.e., simple-liquids, do not reflect the internal features of the real molecules, e.g., structural anisotropy and spatial distribution of charges, which might be crucial for the behavior of real materials. In this paper, we use the new model molecules of simple but anisotropic structure, to studies the effect of dipole moment orientation on the crystallization tendency. Our results indicate that proper orientation of the dipole moment could totally change the stability behavior of the system. Consequently, the exchange of a single atom within the molecule causing the change of dipole moment orientation might be crucial for controlling the crystallization tendency. Moreover, employing the classical nucleation theory, we explain the reason for this behavior. Dipole ; Moment (physics) ; Crystallization ; Orientation (vector space) ; Nucleation ; van der Waals force ; Supercooling ; Anisotropy ; Chemical physics ; Molecular dynamics ; Classical nucleation theory ; Simple (philosophy) ; Materials science ; Molecule ; Statistical physics ; Physics ; Thermodynamics ; Computational chemistry ; Chemistry ; Classical mechanics ; Optics ; Quantum mechanics ; Mathematics Material Dynamics and Properties ; nanoparticles nucleation surface interactions ; Theoretical and Computational Physics
Authors: Yuying Li | Yuan Yao | Guosong Yang | Jun Tang | Gabriela Jaramillo Ayala | Xumin Li | Wenlu Zhang | Qiuyu Han | Tong Yang | Hao Wang | Kevin H. Mayo | Jiyong Su
Source: Frontiers in Microbiology (article, 2020-05-26)
Field: Materials Science — Materials Chemistry

Co-crystal Structure of Thermosynechococcus elongatus Sucrose Phosphate Synthase With UDP and Sucrose-6-Phosphate Provides Insight Into Its Mechanism of Action Involving an Oxocarbenium Ion and the Glycosidic Bond In green species, sucrose can help antagonize abiotic stress. Sucrose phosphate synthase (SPS) is a well-known rate-limiting enzyme in the synthesis of sucrose. To date, however, there is no known crystal structure of SPS from plant or cyanobacteria. In this study, we report the first co-crystal structure of SPS from <i>Thermosynechococcus elongatus</i> with UDP and sucrose-6-phosphate (S6P). Within the catalytic site, the side chains of His158 and Glu331, along with two phosphate groups from UDP, form hydrogen bonds with the four hydroxyl groups of the glucose moiety in S6P. This association causes these four hydroxyl groups to become partially negatively charged, thus promoting formation of the C1 oxocarbenium ion. Breakage of the hydrogen bond between His158 and one of the hydroxyl groups may trigger covalent bond formation between the C1 oxocarbenium ion and the C2 hydroxyl of fructose-6-phosphate. Consistent with our structural model, we observed that two SPS mutants, H158A and E331A, lost all catalytic activity. Moreover, electron density of residues from two loops (loop1 and loop2) in the SPS A-domain was not observed, suggest their dynamic nature. B-factor analysis and molecular dynamics stimulations of the full-length enzyme and A-domain indicate that both loops are crucial for binding and release of substrate and product. In addition, temperature gradient analysis shows that SPS exhibits its highest activity at 70°C, suggesting that this enzyme has the potential of being used in industrial production of S6P. Oxocarbenium ; Chemistry ; Glycosidic bond ; Stereochemistry ; Hydrogen bond ; Sucrose ; Sucrose synthase ; Ribose ; Enzyme ; Catalysis ; Biochemistry ; Organic chemistry ; Molecule Enzyme Structure and Function ; Enzyme Production and Characterization ; Microbial Metabolites in Food Biotechnology
Authors: Lucien Stolze | Jakob Birkedal Wagner | Christian Danvad Damsgaard | Massimo Rolle
Source: Geochimica et Cosmochimica Acta (article, 2020-03-20)
Field: Chemistry — Physical and Theoretical Chemistry

Impact of surface complexation and electrostatic interactions on pH front propagation in silica porous media Porous medium ; Front (military) ; Porosity ; Chemical engineering ; Surface (topology) ; Chemical physics ; Materials science ; Chemistry ; Geology ; Composite material ; Geometry ; Engineering ; Oceanography Electrostatics and Colloid Interactions ; Spectroscopy and Quantum Chemical Studies ; Nanopore and Nanochannel Transport Studies
Authors: Igor Mele | Ivo Pačnik | Klemen Zelič | Jože Moškon | Tomaž Katrašnik
Source: Journal of The Electrochemical Society (article, 2020-04-14)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Advanced Porous Electrode Modelling Framework Based on More Consistent Virtual Representation of the Electrode Topology The paper proposes an advanced continuum level modelling framework characterized by a more consistent virtual representation of electrode topology to enhance prediction capability and generality of porous electrode theory based models. The proposed modelling framework, therefore, establishes the missing link between the mesoscopic scale with a detailed 3D representation of electrode topology and the continuum single cell scale, where interrelation to the real electrode topology was missing. This link is established by elaborating a unified approach for modelling materials with significantly different topologies of active material by virtually creating agglomerates, representing secondary particles, from primary particles. Proposed approach relies on multiparticle size distribution of primary particles and particle-to-particle connectivity. Generality of the proposed modelling framework is demonstrated by simulating LFP and NMC materials featuring significantly different electrode topologies by the same modelling framework while adapting only virtual representation of electrode topologies and intrinsic material properties. Credibility of the proposed modelling framework is confirmed through good agreement with experimental results for various discharge tests. Insightful simulation results also reveal background of the topologically driven low Li utilization at high current densities of the LFP material and topologically driven voltage response difference during the memory effect of different LFP materials. Network topology ; Topology (electrical circuits) ; Electrode ; Generality ; Mesoscopic physics ; Computer science ; Representation (politics) ; Particle (ecology) ; Materials science ; Physics ; Engineering ; Electrical engineering Supercapacitor Materials and Fabrication ; Advancements in Battery Materials ; Advanced Battery Technologies Research
Authors: Danièle Fournier | M. Marangolo | Christian Frétigny
Source: Journal of Applied Physics (article, 2020-12-22)
Field: Materials Science — Materials Chemistry

Measurement of thermal properties of bulk materials and thin films by modulated thermoreflectance (MTR) Thermal conductivity and thermal diffusivity of materials must be known at high accuracy for thermal engineering applications, in order to understand energy dissipation in devices and engines. Thermal conductivity libraries can be unreliable since their reported values may not reflect the complexities of the samples under investigation, and new materials may not yet be listed. Over the past three decades, modulated thermoreflectance (MTR) has emerged and evolved as a reliable, non-contact, and noninvasive technique to measure the thermal properties of a wide range of bulk and thin film materials and their interfaces. This Tutorial discusses the basis of, and recent advances in, the MTR technique, and its applications in the thermal characterization of a variety of materials. MTR experiments use two micrometer-wide laser beams. Experimental data (amplitude and phase vs the offset between the pump and the probe) give information about heat diffusion around the heat source along several tens of micrometers. Heat diffusion equations are used to fit the experimental data and extract the required thermal properties. Importantly, best fit procedures are not always needed because some analytical approximations provide evidence of the required thermal properties. We present many examples (bulk materials, layered sample, etc.) which illustrate this. Thermal diffusivity ; Thermal conductivity ; Laser flash analysis ; Materials science ; Thermal ; Thermal conductivity measurement ; Thermal effusivity ; Micrometer ; Dissipation ; Characterization (materials science) ; Thermal contact conductance ; Optics ; Thermodynamics ; Nanotechnology ; Thermal resistance ; Composite material ; Physics Thermal properties of materials ; Thermography and Photoacoustic Techniques ; Thermal Radiation and Cooling Technologies
Authors: He Sun | Shyam Dwaraknath | Handong Ling | Xiaohui Qu | Patrick Huck | Kristin A. Persson | Sophia E. Hayes
Source: npj Computational Materials (article, 2020-05-12)
Field: Chemistry — Spectroscopy

Enabling materials informatics for 29Si solid-state NMR of crystalline materials Abstract Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for obtaining precise information about the local bonding of materials, but difficult to interpret without a well-vetted dataset of reference spectra. The ability to predict NMR parameters and connect them to three-dimensional local environments is critical for understanding more complex, long-range interactions. New computational methods have revealed structural information available from 29 Si solid-state NMR by generating computed reference spectra for solids. Such predictions are useful for the identification of new silicon-containing compounds, and serve as a starting point for determination of the local environments present in amorphous structures. In this study, we have used 42 silicon sites as a benchmarking set to compare experimentally reported 29 Si solid-state NMR spectra with those computed by CASTEP-NMR and Vienna Ab Initio Simulation Program (VASP). Data-driven approaches enable us to identify the source of discrepancies across a range of experimental and computational results. The information from NMR (in the form of an NMR tensor) has been validated, and in some cases corrected, in an effort to catalog these for the local spectroscopy database infrastructure (LSDI), where over 10,000 29 Si NMR tensors for crystalline materials have been computed. Knowledge of specific tensor values can serve as the basis for executing NMR experiments with precision, optimizing conditions to capture the elements accurately. The ability to predict and compare experimental observables from a wide range of structures can aid researchers in their chemical assignments and structure determination, since the computed values enables the extension beyond tables of typical chemical shift (or shielding) ranges. CASTEP ; NMR spectra database ; Nuclear magnetic resonance spectroscopy ; Solid-state nuclear magnetic resonance ; Nuclear magnetic resonance crystallography ; Tensor (intrinsic definition) ; Materials science ; Computer science ; Spectral line ; Chemistry ; Nuclear magnetic resonance ; Fluorine-19 NMR ; Computational chemistry ; Physics ; Electronic structure ; Mathematics Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography ; High-pressure geophysics and materials
Authors: Weihua Gu | Jiabin Chen | Yue Zhao | Gehuan Wang | Fan Wang | Tengze Zhang | Baoshan Zhang
Source: Scientific Reports (article, 2020-09-29)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Extending effective microwave absorbing bandwidth of CoNi bimetallic alloy derived from binary hydroxides Effectively broadening microwave absorbing frequency of pure magnetic substances remains a huge challenge. Herein, micro-perspective structures can be controlled through a calcination route. Satisfactorily, the composites prepared at the calcination temperature of 900 °C exhibit excellent microwave attenuation performance with a broad working frequency and appropriate paraffin filling ratio. Remarkably, the composites can reach an extremely high reflection loss (RL) value of - 49.79 dB, and the extended effective working frequency range (RL < - 10 dB) of 6.84 GHz can also be obtained. Superb magnetic loss, admirable dielectric loss, sufficient dipole polarization, as well as superior impedance matching should be band together for obtaining ideal microwave absorbers. The CoNi hydroxides derived bimatallic alloy composites were fabricated via a cost-effective and facile synthesis process, and this work aroused inspirations of designing high-performance microwave absorbers for mataining the sustainable development. Materials science ; Calcination ; Microwave ; Reflection loss ; Impedance matching ; Bimetallic strip ; Alloy ; Attenuation ; Stacking ; Dielectric loss ; Dielectric ; Bandwidth (computing) ; Electrical impedance ; Optoelectronics ; Broadband ; Composite material ; Optics ; Computer science ; Composite number ; Nuclear magnetic resonance ; Metallurgy ; Telecommunications ; Electrical engineering Electromagnetic wave absorption materials ; Advanced Antenna and Metasurface Technologies ; Metamaterials and Metasurfaces Applications
Authors: Thomas J. Wenzel
Source: Journal of Chemical Education (article, 2020-07-24)
Field: Chemistry — Physical and Theoretical Chemistry

Collaborative Group Learning in Remotely Taught Analytical Chemistry Courses The use of synchronous remote teaching methods in two undergraduate analytical chemistry courses during the COVID-19 pandemic is described. Classes were convened using cloud-based video conferencing software, and the majority of class time involved students working in small groups on worksheets. All group activities were followed by a whole-class session in which students reported out and discussed the answers. Discussions allowed us to resolve differences in answers among the different groups, discuss interesting questions that arose in some of the groups during their discussion, and summarize the expected answers for questions on the worksheets. The incorporation of a group component into the final exam in one of the courses is described. Students indicated that they preferred the use of synchronous instruction to the asynchronous instruction that occurred in other courses. They also preferred having the opportunity to work in small groups. The active learning materials used in the two courses are available to instructors and students for free through the Analytical Sciences Digital Library. While class sizes in this report were small, the potential for using collaborative groups in larger classes is described. Session (web analytics) ; Class (philosophy) ; Mathematics education ; Asynchronous communication ; Group work ; Computer science ; Videoconferencing ; Collaborative learning ; Group (periodic table) ; Multimedia ; Chemistry ; Psychology ; World Wide Web ; Organic chemistry Various Chemistry Research Topics ; Experimental Learning in Engineering ; Innovative Teaching Methods
Authors: Jessica R. Hoehn | H. J. Lewandowski
Source: Physical Review Physics Education Research (article, 2020-05-11)
Field: Chemistry — Physical and Theoretical Chemistry

Framework of goals for writing in physics lab classes Writing is an integral part of the process of science. In the undergraduate physics curriculum, the most common place that students engage with scientific writing is in lab classes, typically through lab notebooks, reports, and proposals. There has not been much research on why and how we include writing in physics lab classes, and instructors may incorporate writing for a variety of reasons. Through a broader study of multiweek projects in advanced lab classes, we have developed a framework for thinking about and understanding the role of writing in lab classes. This framework defines and describes the breadth of goals for incorporating writing in lab classes, and is a tool we can use to begin to understand why, and subsequently how, we teach scientific writing in physics. Variety (cybernetics) ; Process (computing) ; Scientific writing ; Writing process ; Technical writing ; Scientific thinking Various Chemistry Research Topics ; Science Education and Pedagogy ; Academic Writing and Publishing
Authors: Youngjoon Han | Do Yeob Kim | Kunsik An | Kyung‐Tae Kang | Byeong‐Kwon Ju | Kwan Hyun Cho
Source: Materials (article, 2020-10-24)
Field: Materials Science — Materials Chemistry

Sequential Improvement from Cosolvents Ink Formulation to Vacuum Annealing for Ink-Jet Printed Quantum-Dot Light-Emitting Diodes Optimization of ink-jet printing conditions of quantum-dot (QD) ink by cosolvent process and improvement of quantum-dot light-emitting diodes (QLEDs) characteristics assisted by vacuum annealing were analyzed in this research. A cosolvent process of hexane and ortho-dichlorobenzene (oDCB) was optimized at the ratio of 1:2, and ink-jetting properties were analyzed using the Ohnesorge number based on the parameters of viscosity and surface tension. However, we found that these cosolvents systems cause an increase in the boiling point and a decrease in the vapor pressure, which influence the annealing characteristics of the QD emission layer (EML). Therefore, we investigated QLEDs' performance depending on the annealing condition for ink-jet printed QD EML prepared using cosolvents systems of hexane and oDCB. We enhanced the quality of QD EML and device performance of QLEDs by a vacuum annealing process, which was used to prevent exposure to moisture and oxygen and to promote effective evaporation of solvent in QD EML. As a result, the characteristics of QLEDs formed using ink-jet printed QD EML annealed under vacuum environment increased luminescence (L), current efficiency (CE), external quantum efficiency (EQE), and lifetime (LT<sub>50</sub>) by 30.51%, 33.7%, 21.70%, and 181.97%, respectively, compared to QLEDs annealed under air environment. Inkwell ; Quantum dot ; Materials science ; Optoelectronics ; 3d printed ; Annealing (glass) ; Light-emitting diode ; 3D printing ; Diode ; Inkjet printing ; Nanotechnology ; Composite material Quantum Dots Synthesis And Properties ; Nanomaterials and Printing Technologies ; Innovative Microfluidic and Catalytic Techniques Innovation