jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Shane Austin | Crystal-Ann Millar | Sherena Christmas
Source: Essays in Biochemistry (article, 2022-03-10)
Field: Chemistry — Physical and Theoretical Chemistry

Case study: Perspectives on the use of LEGO® bricks in the biochemistry classroom The use of LEGO® bricks in the higher education classroom has increased in the last two decades. This is no different in the STEM classroom and several disciplines, including physics, chemistry, and biology, have all made use of LEGO® bricks in some way to create models for active learning activities. Currently, the discipline to make the greatest use of LEGO® bricks is chemistry; only limited examples exist in biochemistry and the molecular life sciences. Here, we present the use of a LEGO® brick modelling activity in the introductory biochemistry classroom during the teaching of metabolism. We present student comments on the activity and the models that were generated by the students. Additionally, we focus on other instructor and project student-designed models for the teaching of ATP synthesis, gene regulation and restriction digestion. Interestingly, both the gene regulation and restriction digest activities were generated with the help of undergraduate students or recent graduates, by applying a backward design approach. This case study seeks to encourage more molecular life science educators to adopt the use of LEGO® bricks in their classrooms to engage in more active learning. Brick ; Focus (optics) ; Active learning (machine learning) ; Authentic learning ; Undergraduate education Various Chemistry Research Topics ; Science Education and Pedagogy ; Cancer and biochemical research
Authors: Daniel L. Silverio | Matthew J. Mistretta | Scott P. Buzzolani
Source: Journal of Chemical Education (article, 2022-11-22)
Field: Chemistry — Physical and Theoretical Chemistry

To the Literature and Beyond: Teaching Advanced Organic Chemistry at a Primarily Undergraduate Institution Offering an advanced organic chemistry course at a primarily undergraduate institution poses a challenge of condensing graduate organic synthesis into one course. This course was designed so students choose and read recent total synthesis papers from the literature in lieu of relying on a textbook or other pre-existing course materials. Following the reading, students are required to propose a reasonable arrow-pushing mechanism for each step in the paper. The professor guides students on how to develop the ability to use resources (e.g., the primary literature, books, search engines, etc.) to propose mechanisms for reactions that are new to the students. In-class group work is implemented to promote active learning of complex topics. All mechanism proposals are presented to the entire class so that students become competent at communicating complex topics to others. Students not only learn many new reagents, reactions, and mechanisms relevant to modern organic synthesis but more importantly become proficient in finding detailed information on unfamiliar topics, a skill valuable to any scholar. As the course does not require the creation of materials such as problem sets or lecture notes, it can be taught with minimal preparation and work during the week by an instructor holding a PhD in synthetic organic chemistry or a closely related field. Class (philosophy) ; Institution ; Reading (process) ; Mathematics education ; Chemistry ; Graduate students ; Computer science ; Psychology ; Pedagogy ; Sociology ; Political science ; Artificial intelligence Various Chemistry Research Topics ; Innovative Teaching and Learning Methods ; Innovative Teaching Methods
Authors: Issa I. Salame | David A. Krauss | Shafic Suleman
Source: IJCER (International Journal of Chemistry Education Research) (article, 2022-10-10)
Field: Chemistry — Physical and Theoretical Chemistry

Examining learning difficulties and alternative conceptions students face in learning about hybridization in organic chemistry Chemistry education research has demonstrated that chemistry concepts are abstract, complex, and challenging for students to learn and understand. Chemistry is the branch of science that deals with the nature and behavior of atoms, and bond formation and hybridization both play a crucial role in the discipline. The concept of hybridization deals with the description of the formation of hybrid orbitals, the prediction of bond angles and molecular geometry, and the reactivity of some organic compounds. Development of conceptual understanding of hybridization is important for effective learning about bond formation, molecular structure, bond angle, acidity, and reactivity. This research study aimed to examine alternative conceptions that students hold; the challenges that students face in learning about hybridization; and the strategies that they use to solve hybridization problems. The investigation took place at the City College of New York, an urban, minority-serving institute. Our method of data collection comprised a survey made up of Likert-type, open-ended questions as well as a hybridization-related set of problems. The number of research participants was n = 103. Our research findings suggest that developing conceptual understanding of organic chemistry concepts such hybridization and resonance structures, then relating it to the structure of molecules, is crucial to its function. The presentation of concepts such as hybridization in an oversimplified manner and students’ reliance on memorization in learning can hinder students’ development of conceptual understanding and meaningful learning. Students misestimate their competencies and abilities which can negatively impact poor performers and prevent them from addressing deficiencies in learning about hybridization. We suggest that instructors present the topic of hybridization at the three levels of representations, provide students with opportunities for active learning and knowledge construction, and nurture students’ visualization of atomic and hybrid orbitals. Keywords: science education, alternative conceptions, hybridization, atomic orbitals Memorization ; Presentation (obstetrics) ; Mathematics education ; Chemistry ; Face (sociological concept) ; Psychology ; Set (abstract data type) ; Data presentation ; Chemistry education ; Data collection ; Sociology ; Computer science ; Social psychology ; Medicine ; Social science Various Chemistry Research Topics
Authors: G. Lohöfer | Xiao Xiao
Source: Physics of Fluids (article, 2022-07-01)
Field: Materials Science — Materials Chemistry

Residual fluid flow in liquid metallic droplets processed in the space station electromagnetic levitation facility The electromagnetic levitation facility on board the International Space Station is used to investigate contactlessly and without gravity-induced convection thermophysical properties and microstructure formations of hot, highly reactive metallic liquids. Despite the widely forceless microgravity environment, the small remaining electromagnetic levitation forces still drive residual convective fluid flows inside the levitated droplet, which may disturb the measurements. Thus, the knowledge of the flow velocities is critical to interpret and evaluate the measurement results. In previous investigations of Xiao and co-workers, a great amount of numerical magneto hydrodynamics calculations were performed with many different material properties and source force terms. The results for the maximum flow velocities hereof were analytically characterized by surrogate models consisting of multi-dimensional, high-order regression analysis. The present work offers another analytical description of these numerical results. Derived based on physical relations, it provides a simpler and physically more illustrative presentation. Levitation ; Physics ; Mechanics ; Magnetic levitation ; Convection ; Flow (mathematics) ; Residual ; Liquid metal ; Fluid dynamics ; Work (physics) ; Classical mechanics ; Thermodynamics ; Materials science ; Magnet Solidification and crystal growth phenomena ; Magnetic and Electromagnetic Effects ; Metallurgical Processes and Thermodynamics
Authors: Peng Liu | Yuwen Ouyang | Jiafu Deng
Source: IEEE Transactions on Industrial Electronics (article, 2022-09-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Demarcation Method for Magnetostatic Model of Long-Stroke Moving-Iron Proportional Electromagnetic Actuator To improve the precision of the magnetostatic finite element model for the long-stroke moving-iron proportional electromagnetic actuator, on the basis of three characteristic parameters, including the initial relative permeability of materials μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> , saturation magnetic polarization <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> , and knee point adjustment coefficient of magnetizing curve <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</i> , this article puts forward an efficient demarcation method by virtually remodeling the magnetizing curve of soft magnetic material for the actuator and combining surrogate model and optimization technique. Then, the demarcation mathematical models based on surrogate model are built while taking μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> , <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> , and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</i> of the soft magnetic material 1 for the main magnetic loop of the actuator as calibration parameters, and regarding the relative root-mean-square error and relative maximum absolute error of electromagnetic force under the typical operating conditions of the actuator as targets. Finally, the demarcation mathematical models are solved by downhill simplex method and the final calibration parameters are confirmed. The results indicate that the relative root-mean-square error, relative maximum absolute error, and relative average absolute error of finite element model after demarcation are 2.7, 4.3, and 2.3%, respectively, decreasing of 57.1, 58.7, and 39.5% with respect to the initial finite element model of the actuator. Computer science ; Artificial intelligence ; Algorithm Magnetic Properties and Applications ; Electric Motor Design and Analysis ; Non-Destructive Testing Techniques
Authors: V. Merevis | K. Margaronis | Vissarion Papadopoulos
Source: Mechanics of Advanced Materials and Structures (article, 2022-05-13)
Field: Materials Science — Materials Chemistry

Thermomechanical analysis of the effect of contact forces in heat conduction of composite materials through multiscale contact finite element modeling The present study proposes a thermomechanical surface contact finite element formulation for studying interfacial heat conductance in correlation to micromechanical contact forces. The proposed methodology is applied for modeling heat surface conductivity of Carbon Nanotubes (CNT). The atomic lattice of CNTs is initially modeled using the molecular structural mechanics approach and reduced to an equivalent 2D continuum element. The equivalent 2D continuum element is used as a robust and efficient surrogate model for the construction of full length CNTs in contact. Coupled structural and heat pde’s have been used to describe the corresponding thermomechanical problem which are discretized using 2D quadrilateral finite elements, along with surface contact elements based on the Node to Node and Node to Segment formulations. The problem has been treated as a nonlinear steady state problem and solved in the frame of a Newton-Raphson incremental-iterative scheme. Extensive sensitivity analysis was performed with respect to several influencing parameters, such as initial contact angle, boundary conditions and CNT overlapping. Based on this analysis, the effect of overlapping and approaching angle on the total heat exchange was quantified. It has been demonstrated that in most cases, increasing the total contact force can produce an almost linear increase in heat exchange. However, in cases of small approaching angles between CNTs an extensive contact force could heavily deform the contacting geometries producing a non-linear heat exchange mechanism. Finite element method ; Materials science ; Thermal conduction ; Mechanics ; Discretization ; Thermal contact ; Boundary value problem ; Thermal contact conductance ; Contact angle ; Continuum mechanics ; Heat transfer ; Composite material ; Structural engineering ; Mathematics ; Mathematical analysis ; Physics ; Engineering ; Thermal resistance Thermal properties of materials ; Adhesion, Friction, and Surface Interactions ; Composite Material Mechanics
Authors: J. R. Capers | Dean A. Patient | S. A. R. Horsley
Source: Physical review. A/Physical review, A (article, 2022-11-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Inverse design in the complex plane: Manipulating quasinormal modes Utilizing the fact that the frequency response of a material can be decomposed into the quasinormal modes supported by the system, we present two methods to directly manipulate the complex frequencies of quasinormal modes in the complex plane. We first consider an ``eigenpermittivity'' approach that allows one to find how to shift the permittivity of the structure everywhere in order to place a single quasinormal mode at a desired complex frequency. Secondly, we then use perturbation theory for quasinormal modes to iteratively change the structure until a given selection of quasinormal modes occurs at desired complex frequencies. Complex plane ; Physics ; Perturbation (astronomy) ; Normal mode ; Perturbation theory (quantum mechanics) ; Inverse ; Complex system ; Quasinormal mode ; Statistical physics ; Theoretical physics ; Classical mechanics ; Mathematical analysis ; Quantum mechanics ; Mathematics ; Computer science ; Geometry Metamaterials and Metasurfaces Applications ; Electromagnetic Scattering and Analysis ; Acoustic Wave Phenomena Research
Authors: Stanisław Pawłowski | M. Mączka
Source: Materials (article, 2022-08-19)
Field: Chemistry — Spectroscopy

Optimisation of QCL Structures Modelling by Polynomial Approximation Modelling of quantum cascade laser (QCL) structures, despite a regular progress in the field, still remains a complex task in both analytical and numerical aspects. Computer simulations of such nanodevices require large operating memories and effective algorithms to be applied. Promisingly, by applying semi-analytical polynomial approximation method to computing potential, wave functions and electron charge distribution, accurate results and quick convergence of the self-consistent solution for the Schrödinger and Poisson equations are reachable. Additionally, such an approach makes the respective numerical models competitively effective. For contemporary QCL structures, with quantum wells quite typically forming complex systems, a special approach to determining self energies and coefficients of approximating polynomials is required. Under this paper we have analysed whether the polynomial approximation method can be successfully applied to solving the Schrödinger equation in QCL. A new algorithm for determining self energies has been proposed and a new method has been optimised for the researched structures. The developed solutions have been implemented as a new module for the finite model of the superlattice (FMSL) and tested on the QCL emitting light in the mid-infrared range. Convergence (economics) ; Polynomial ; Poisson's equation ; Applied mathematics ; Range (aeronautics) ; Quantum cascade laser ; Quantum ; Cascade ; Computer science ; Algorithm ; Mathematics ; Mathematical analysis ; Physics ; Materials science ; Quantum mechanics ; Engineering Spectroscopy and Laser Applications ; Semiconductor Lasers and Optical Devices ; Laser Design and Applications
Authors: Ruicong Xu | Songbai Cheng
Source: Science and Technology of Nuclear Installations (article, 2022-08-22)
Field: Materials Science — Materials Chemistry

Debris Bed Self-Leveling Mechanism and Characteristics for Core Disruptive Accident of Sodium-Cooled Fast Reactor: Review of Experimental and Modeling Investigations Evaluations of the Core Disruptive Accident (CDA) are significantly important for safety analysis of Sodium-cooled Fast Reactor (SFR) despite the very low probability of occurrence for CDA. During the material-relocation phase in CDA of SFR, the molten materials are possibly released from the core region into subcooled sodium, subsequently forming the debris bed on the lower part of the reactor vessel after being quenched and fragmented. The accumulated high-temperature debris with decay heat can cause sodium coolant boiling, leading to the so-called “debris bed self-leveling behavior” during which the shape of the debris bed becomes flattered (leveling). It is important to investigate the debris bed self-leveling behavior due to its potential capacity to induce the transfer of debris and affect the ability of cooling and criticality of the debris bed. Thus, in recent years, valuable knowledge concerning the mechanism and characteristics of this behavior was accumulated through lots of experimental results and modeling developments. Aimed at providing a valuable guideline for future investigations on this issue, in this study, the past experimental and modeling investigations on debris bed self-leveling mechanism and characteristics are systematically summarized and reviewed, and some future remarks are also proposed to promote the progression of further research for SFR severe accident analysis. Debris ; Subcooling ; Coolant ; Corium ; Nuclear engineering ; Reactor pressure vessel ; Boiling ; Mechanism (biology) ; Environmental science ; Core (optical fiber) ; Heat transfer ; Forensic engineering ; Materials science ; Engineering ; Mechanical engineering ; Geology ; Chemistry ; Mechanics Nuclear Materials and Properties ; Nuclear reactor physics and engineering ; Nuclear Engineering Thermal-Hydraulics
Authors: Ekta Jagtiani
Source: Advances in Biochips (article, 2022-01-01)
Field: Materials Science — Biomaterials

Cellulose based smart sensors Cellulose fibres, cellulose nanofibers, cellulose nanocrystals and cellulose derivatives are all examples of cellulose-based materialsthat display superior characteristics with a number of desirable properties, including biodegradability, sustainability, biocompatibility, thermal properties , optical transparency, flexibility, high mechanical strength, high porosity,hydrophilicity, a large surface area and broad chemical modification capabilities. "Smart" materials based on cellulose created by the chemical changes and physical incorporation/blending techniques offer numerous advantages, most notably their intelligent responses to environmental stimuli. Conductive networks are formed in cellulose-based composite materials by combining or coating conductive materials with the cellulose components or by directly carbonising the cellulose materials. Numerous nanopaper-based optical sensing platforms are explained and how they can be tailored to exhibit plasmonic or photoluminescent features suitable for sensing applications using nanomaterials or as biomaterials. The responsiveness of these "smart" materials to pH, temperature, light, electricity, magnetic fields and mechanical forces, among other parameters, is also reviewed, as were their applications as drug delivery systems, hydrogels, electronic active papers, sensors, shape memory materials, smart membranes, etc. Cellulose ; Materials science ; Nanocellulose ; Smart material ; Nanomaterials ; Biocompatibility ; Nanofiber ; Nanotechnology ; Bacterial cellulose ; Porosity ; Self-healing hydrogels ; Composite material ; Chemical engineering ; Polymer chemistry Advanced Cellulose Research Studies ; Advanced Sensor and Energy Harvesting Materials ; Nanocomposite Films for Food Packaging
Authors: Trent R. Graham | Joel Castillo | Sergey I. Sinkov | Artem V. Gelis | Gregg J. Lumetta | Herman Cho
Source: Inorganic Chemistry (article, 2022-12-30)
Field: Chemistry — Inorganic Chemistry

Multiplicity of Th(IV) and U(VI) HEH[EHP] Chelates at Low Temperatures from Concentrated Nitric Acid Extractions Organophosphorus extractants have been widely investigated for lanthanide recovery from ore and for application in the reprocessing of spent nuclear fuel, such as in Advanced TALSPEAK schemes. Determining the speciation of the extracted metal complex in the organic phase remains a significant challenge. A better understanding of the variability of HEH[EHP]-actinide complexes and the speciation of chelates for tetra- and hexavalent actinides can improve the predictability of actinide phase transfer in such biphasic systems. In this study, the extraction of Th(IV) and U(VI) from nitric acid media using HEH[EHP] in heptane is examined. The distribution ratio as a function of nitric acid concentration was quantified using UV-vis spectroscopy, and then the speciation of HEH[EHP]-metal complexes in the organic phase was investigated using Fourier transform infrared (FTIR) spectroscopy and low-temperature <sup>31</sup>P nuclear magnetic resonance (NMR) spectroscopy. In addition to perturbation of the vibrational modes proximal to the phosphonic moiety in HEH[EHP] in the FTIR spectra, the appearance of a nitrate signal was found in the organic phase following extraction from the highest acidity conditions for U(VI). The <sup>31</sup>P NMR spectra of the organic phase at a low temperature (-70 °C) exhibited a surprising number (<i>n</i>) of resonances (<i>n</i> ≥ 7 for Th(IV) and <i>n</i> ≥ 11 for U(VI)), with the distribution between these resonances changing with the initial concentration of nitric acid in the aqueous phase. These results indicate that the compositions of the inner and outer spheres of the extracted actinides in the organic phase are more diverse than initially thought. Chemistry ; Nitric acid ; Actinide ; Inorganic chemistry ; Humic acid ; Aqueous two-phase system ; Chelation ; Nuclear magnetic resonance spectroscopy ; Fourier transform infrared spectroscopy ; Nuclear chemistry ; Metal ; Analytical Chemistry (journal) ; Phase (matter) ; Stereochemistry ; Organic chemistry Radioactive element chemistry and processing ; Nuclear Materials and Properties ; Extraction and Separation Processes