jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Daniel Broberg
Source: eScholarship (California Digital Library) (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Point Defect Engineering of Energy Materials from First-Principles Calculations Atomic scale imperfections, know as point defects, dictate the performance and efficiency of many modern energy materials. The challenges of climate change require the continued improvement and identification of materials which can have point defects engineered in a favorable fashion for the application of interest. With the rise of computer-aided materials design, the possibility of performing high-throughput, first-principles computation on point defects remains an attractive direction for improved screening of new energy materials. Yet major barriers have prevented the large scale implementation of point defect calculations in non-metals - namely, errors arising from the finite size of the computation cell, compounded with errors associated with the underestimation of the band gap. Moreover, the lack of an organized computational framework for storing and analyzing such calculations, as well as the lack of a reliable benchmark for understanding the quantities which can be reliably computed, have prevented high-throughput point defect calculations from being performed in a practical context. In this dissertation, the notion of performing first principles calculations of point defects in semiconductors and insulators in a high-throughput format is investigated. This begins with an overview of the theoretical requirements for performing first principles computation of defects, as well as the presentation of a set of open source command line tools for doing the same. Then three different application areas in the energy space - thermoelectrics for waste heat recovery, solid state electrolyte batteries, and solar cells - are explored with first principles calculations of point defects. Finally, scaling of the previously presented command line tools to a fully automated framework is demonstrated and used for a large benchmark study of fully-automated point defect calculations with semi-local functionals as compared to a set of previously published point defect calculations with hybrid-functionals. This benchmark work outlines the strengths and weaknesses associated with such an automation framework, and advocates for the use of such a framework for qualitative screening of doping limits and general carrier type for high-throughput computational discovery and design of new energy materials. Computer science ; Point (geometry) ; Context (archaeology) ; Computation ; Throughput ; Scale (ratio) ; Computational science ; Computer engineering ; Mechanical engineering ; Engineering ; Algorithm ; Physics Machine Learning in Materials Science ; Electron and X-Ray Spectroscopy Techniques
Authors: S. Joseph Poon | Jian He
Source: arXiv (Cornell University) (preprint, 2019-11-09)
Field: Materials Science — Materials Chemistry

Multi-Principal-Element Approach to High-Performance Thermoelectric Materials High-entropy alloys are characterized by high configurational entropy. Since the discovery of high-entropy alloys (HEA) in 2004, entropy engineering has provided a promising direction for exploiting composition, lattice disorder, band structure, and microstructure effects to advance thermoelectric performance. This review discusses the impact of entropy on thermoelectric properties and looks back at the role of multi-principal-element alloys, a weaker version of HEA, on the development of compositionally complex thermoelectric alloys in achieving high thermoelectric performance. The experimental and theoretical efforts in a wide range of material systems such as TAGS, LAST, half-Heusler, liquid-like copper chalcogenides, SnTe, and CuInTe2 chalcopyrites provide insights into the entropy engineering approach and also promise an emerging paradigm of high-entropy thermoelectrics. Thermoelectric effect ; Thermoelectric materials ; Materials science ; High entropy alloys ; Microstructure ; Entropy (arrow of time) ; Thermodynamics ; Engineering physics ; Condensed matter physics ; Mechanical engineering ; Metallurgy ; Physics ; Engineering Advanced Thermoelectric Materials and Devices ; nanoparticles nucleation surface interactions ; High Entropy Alloys Studies
Authors: José A. Bravo | José L. Vila
Source: Revista Boliviana de Química (article, 2019-08-30)
Field: Chemistry — Organic Chemistry

TEORÍA FUNCIONAL DE LA DENSIDAD: ESTUDIO ASISTIDO POR COMPUTADORA DE LOSESPECTROS DE RMN 1H Y 13C DEL 4-HIDROXI-3-(3’-METIL-2’-BUTENIL)ACETOFENONA AISLADA DE SENECIO GRAVEOLENS Y SU DERIVADO SINTETIZADO POR MICROONDAS, 4’-HIDROXI-3’-(3-METIL-2-BUTENIL)CHALCONA. Utilizando la teoría funcional de la densidad, se realizó el estudio espectral asistido por computadora de los desplazamientos () químicos de RMN 1H y 13C, y de algunas otras propiedades moleculares de la 4-hidroxi-3-(3-metil-2-butenil)acetofenona 1 y de la 4'-hidroxi-3'-(3-metil-2-butenil)chalcona 2. El compuesto 1 fue aislado en un trabajo previo de las partes áreas de Senecio graveolens y su derivado sintético 2 fue obtenido por irradiación con microondas de 1 con benzaldehído, tal como lo publicaron previamente los autores. Los cálculos arrojaron resultados confiables que están en buena correlación con los datos experimentales. Esta es una buena base para la colaboración entre químicos experimentales y cuánticos. Siguiendo las tendencias actuales en la descripción de datos de RMN para moléculas pequeñas, para su lectura y almacenamiento de datos de correlación 2D accesibles por computadora y humanos, resumimos los datos experimentales de RMN 1D y 2D de 1 y 2. Physics ; Humanities ; Philosophy Synthesis and Biological Evaluation ; Synthesis and biological activity ; Structural and Chemical Analysis of Organic and Inorganic Compounds
Authors: Edward Price
Source: Journal of International Crisis and Risk Communication Research (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

A Complete Approach to Predict Biodistribution of Nanomaterials Within Animal Species from In-vitro Data Smart drug-design for antibody and nanomaterial-based therapies allows for optimization of drug efficacy and more efficient early-stage pre-clinical trials. The ideal drug must display maximum efficacy at target tissue sites, but to track and predict distribution to these sites, one must have a mechanistic understanding of the kinetics involved with the individual cells of the tissue itself. This process can be tracked through biological simulations coupled with in-vitro approaches, which result in a rapid and efficient in-depth understanding of drug transport within tissue vasculature and cellular environment. As a result, it becomes possible to predict drug biodistribution within live animal tissue cells without the need for animal studies. Herein, we use in-vitro assays to translate transport kinetics to whole-body animal simulations to predict drug distribution from vasculature into individual tissue cells for the first time. Our approach is based on rate constants obtained from an in-vitro assay that accounts for cell-induced degradation, which are translated to a complete animal simulation to predict nanomedicine biodistribution at the single cell level. This approach delivers predictions for therapies of varying size and type for multiple species of animals solely from in-vitro data. Thus, we expect this work to assist in refining, reducing, and replacing animal testing, while at the same time, giving scientists a new perspective during early stages of drug development. Biodistribution ; In vitro ; Computer science ; Chemistry ; Computational biology ; Nanotechnology ; Biology ; Materials science ; Biochemistry Nanoparticles: synthesis and applications ; Heavy Metal Exposure and Toxicity ; Trace Elements in Health
Authors: Ch. Pulka | Mykola Pіdgurskyi | Viktor Senchyshyn | M.V. Sharyk | V.Ya. Gavrylyuk
Source: The Paton Welding Journal (article, 2019-10-28)
Field: Materials Science — General Materials Science

Effect of horizontal mechanical vibration on service properties of deposited metal The Paton Welding Journal, 2019, №10. International Scientific-Technical and Production Journal «The Paton Welding Journal» «The Paton Welding Journal» has been published monthly since 2000 in English, ISSN 0957-798X. «The Paton Welding Journal» is a cover-to-cover English translation of the «Avtomaticheskaya Svarka» (Automatic Welding) journal. The «Avtomaticheskaya Svarka» journal has been published monthly since 1948 in Russian, ISSN 005-111X. Materials science ; Vibration ; Metal ; Mechanical vibration ; Composite material ; Metallurgy ; Acoustics ; Physics Material Properties and Applications ; Additive Manufacturing and 3D Printing Technologies ; Engineering Technology and Methodologies
Authors: Sen Yao | Hunter Moseley
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2019-04-26)
Field: Chemistry — Spectroscopy

Finding high-quality metal ion-centric regions across the worldwide Protein Data Bank Abstract As the number of macromolecular structures in the worldwide Protein Data Bank (wwPDB) continues to grow rapidly, more attention is being paid to the quality of its data, especially for use in aggregated structural and dynamics analyses. In this study, we systematically analyzed 3.5 Å regions around all metal ions across all PDB entries with supporting electron density maps available from the PDB in Europe. All resulting metal ion-centric regions were evaluated with respect to four quality-control criteria involving electron density resolution, atom occupancy, symmetry atom exclusion, and regional electron density discrepancy. The resulting list of metal binding sites passing all four criteria possess high regional structural quality and should be beneficial to a wide variety of downstream analyses. This study demonstrates an approach for the pan-PDB evaluation of metal binding site structural quality with respect to underlying x-ray crystallographic experimental data represented in available electron density maps of proteins. For non-crystallographers in particular, we hope to change the focus and discussion of structural quality from a global evaluation to a regional evaluation, since all structural entries in the wwPDB appear to have both regions of high and low structural quality. Protein Data Bank ; Protein Data Bank (RCSB PDB) ; Quality (philosophy) ; Structural bioinformatics ; Electron density ; Atom (system on chip) ; Ion ; Crystallography ; Data mining ; Chemistry ; Chemical physics ; Computer science ; Physics ; Protein structure ; Electron ; Biochemistry Mass Spectrometry Techniques and Applications ; Enzyme Structure and Function ; Protein Structure and Dynamics
Authors: Ray Hua Horng
Source: Modern Concepts in Material Science (article, 2019-12-04)
Field: Materials Science — Materials Chemistry

Modern Concepts in Material Science With the improved technologies day by day, it will influence the development and evolution of today society and make life more convenient. From the data center, Internet of Things, robots, selfdriving cars, artificial intelligence, smart medical care, Geriatric care etc. Medical science ; Robot ; The Internet ; Center (category theory) ; Internet of Things ; Computer science ; Engineering ethics ; Engineering management ; Engineering ; Data science ; Artificial intelligence ; Medicine ; World Wide Web ; Medical education ; Chemistry Diamond and Carbon-based Materials Research ; Machine Learning in Materials Science
Authors: Yelena Blinayeva | Saule Smailova
Source: Informatyka Automatyka Pomiary w Gospodarce i Ochronie Środowiska (article, 2019-06-21)
Field: Chemistry — Analytical Chemistry

MODELING OF PROCESSES IN CRUDE OIL TREATED WITH LOW-FREQUENCY SOUNDS These days new methods of purification of crude oil from paraffin are being sought to improve the quality of oil, reduce its cost and optimize the processes of technological preparation of oil. The paper describes the method of conducting an experiment to study the impact of low-frequency sounds on oil samples of the Zhanazhol field, and presents the results of experiments, the input parameters of the experiment (exposure time and frequency of infrasound), at which the maximum reduction of the kinematic viscosity of oil is achieved. Further study of processes in crude oil under the influence of low-frequency sounds is planned to be investigated in Comsol Multiphysics®. Multiphysics ; Crude oil ; Infrasound ; Petroleum engineering ; Environmental science ; Oil field ; Viscosity ; Acoustics ; Oil viscosity ; Low frequency ; Process engineering ; Computer science ; Pulp and paper industry ; Materials science ; Engineering ; Composite material ; Physics ; Telecommunications ; Structural engineering ; Finite element method Petroleum Processing and Analysis ; Enhanced Oil Recovery Techniques ; Oil and Gas Production Techniques
Authors: Jacqueline Casey Mohen
Source: Rowan Digitals Works (Rowan University) (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Investigating color additive molecules for pharmaceutical and cosmetic applications: A comparison of theoretical and experimental UV-visible absorbance spectra in tunable solvents Color additive molecules have widespread applications ranging from ingestible foods and pharmaceutics to non-ingestible cosmetics and other naturally or synthetically developed consumer products available worldwide. Certification for approved use of color additives varies globally; therefore, a feasible method to analyze existing color additives or to design novel color additive molecules with enhanced or otherwise desired physicochemical properties (such as hue) is in high demand for universal adoption. The studies herein provide sufficient proof that density functional theory and time-dependent density functional theory serve as effective predictive modeling techniques for generating theoretical maximum absorbance spectral peak responsivity for a single color additive molecule structure in the virtual workspace, as well as for multiple (heterodimeric and heterotrimeric) structures represented simultaneously. Furthermore, DFT and TD-DFT can be used to analyze changes in hue attributed to structural anomalies in molecules due to tautomerism, vibronic effects, intra- or intermolecular interactions, implicit or explicit solvation effects, or charge transfer effects on the structure represented in a given solvent or in vapor phase. Advancements in computational processing make incorporation of these and similar advanced ab initio quantum chemical methods more tangible for the modern pharmaceutical or cosmetic formulator to use in perfecting batch hue. Absorbance ; Molecule ; Ultraviolet visible spectroscopy ; Spectral line ; Visible spectrum ; Chemistry ; Photochemistry ; Materials science ; Optoelectronics ; Organic chemistry ; Chromatography ; Physics Photochromic and Fluorescence Chemistry
Authors: Jessica L. McKinley
Source: eScholarship (California Digital Library) (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

The Importance of Thermal Expansion in the Simulation of Molecular Crystals Molecular crystals are commonly used in pharmaceuticals, organic semi-conductor materials, explosives, and many other areas of Chemistry. Molecular crystal packing interactions are governed by subtle balances between intra- and intermolecular interactions, providing a severe challenge for theoretical crystal structure modeling. Additionally, molecular crystals can expand appreciably upon heating due to both zero-point and thermal vibrational motion, yet this expansion is often neglected in molecular crystal modeling studies. Quasi-harmonic (QHA) approaches provide an economical route to modeling the temperature dependence of molecular crystal structures and properties but can be cost-prohibitive when evaluated at higher levels of theory.In this thesis, we introduce a hierarchy of models (tiered-QHA) in which the energies, geometries, and phonons are computed either with correlated methods (such as second-order Møller-Plesset perturbation theory (MP2)) or density functional theory (DFT). We examine which combinations produce useful predictions for properties such as the molar volume, enthalpy, and entropy as a function of temperature. Compared to performing the entire calculation using pure MP2, this leads to a modest loss in chemical accuracy and provides a necessary increase in the speed of computation. Additionally, employing this method increases the system size we can feasibly simulate to over 100 atoms per central unit cell, allowing us to simulate pharmaceutically-relevant molecular crystals. We apply this new tiered-QHA method to examine the phase-transition properties of α- and β- resorcinol.Finally, neglecting thermal expansion can significantly affect simulated spectroscopic properties. In particular, nuclear magnetic resonance (NMR) chemical shift predictions will suffer since a small change in atomic position translates to a large change in the chemical shift spectra. We investigate how accounting for thermal expansion in molecular crystals via the QHA refines isotropic 68 13C and 28 15N predicted chemical shifts on a number of molecular crystals. We demonstrate that chemical shifts computed using quasi-harmonic room-temperature structures rival those based on the experimental unit cell parameters. We also show increased discrimination between candidate structures amongst five theophylline structures that were generated via crystal structure prediction. Intermolecular force ; Statistical physics ; Crystal (programming language) ; Thermal expansion ; Density functional theory ; Thermodynamics ; Chemistry ; Computation ; Negative thermal expansion ; Enthalpy ; Chemical physics ; Molecule ; Computational chemistry ; Physics ; Quantum mechanics ; Computer science ; Algorithm Solid-state spectroscopy and crystallography ; Nonlinear Optical Materials Research
Authors: Farah Assadian | Али Ниази
Source: Journal of the Mexican Chemical Society (article, 2019-12-09)
Field: Chemistry — Analytical Chemistry

Genetic Algorithms-Based Approach for Wavelength Selection in Simultaneous Spectrofluorimetric Determination of Ofloxacin and Riboflavin in biological samples by Partial Least-Squares This study shows that genetic algorithm (GA) is a suitable method for selecting wavelengths for partial least squares (PLS) calibration of mixtures with almost identical spectra without loss of prediction capacity employing spectrofluorimetric method. A training set of mixtures containing different concentrations of ofloxacin (OFL) and riboflavin (B2) were prepared to be used as calibration set to check the prediction ability of GA-PLS models due to spectral overlapping of these constituents. Each model was validated using a validation set and then real samples were analyzed. Linear calibration curves were obtained in the 0.5-5.0 and 2.0-10.0 µg mL-1 range for ofloxacin and riboflavin, respectively. To preprocess the data matrices, the orthogonal signal correction (OSC) was used and the analysis results were statistically compared. The methods accuracy for simultaneous determination of ofloxacin and riboflavin, were evaluated by the root mean square errors of prediction (RMSEP) which were 0.0868 and 0.158 for ofloxacin and riboflavin, respectively, and relative standard error of prediction (RSEP) which were 2.738 and 2.846 for ofloxacin and riboflavin, respectively using OSC-GA-PLS models. This procedure allows the simultaneous determination of OFL and B2 in human urine and serum samples with good reliability of the determination. Partial least squares regression ; Ofloxacin ; Riboflavin ; Calibration ; Chromatography ; Chemistry ; Mean squared error ; Analytical Chemistry (journal) ; Mathematics ; Statistics Spectroscopy and Chemometric Analyses ; Analytical Chemistry and Chromatography ; Analytical Methods in Pharmaceuticals
Authors: Gopal B. Sosa
Source:  (article, 2019-04-11)
Field: Chemistry — Analytical Chemistry

A COMPREHENSIV REVIEW ON ANALYTICAL METHODS FOR ESTIMATION OF DEXTROMETHORPHAN AND SITAGLIPTIN Dextromethorphan Hydrobromide is a non-selective serotonin uptake inhibitor and an agonist of sigma-1 receptor, and acts centrally to elevate threshold for coughing. Sitagliptin, the dipeptidyl peptidase-4 (DPP-4) inhibitor, is used to treat type 2 diabetes. Their physicochemical characteristics, modes of action, and clinical significance are all thoroughly covered in this review. For the evaluation of both medications separately and in combination with other agents, it also provides a summary of official pharmacopeial procedures and reported analytical techniques, such as HPLC, RP-HPLC, HPTLC, Spectrophotometry, and Micellar Liquid Chromatography. The progress and difficulties in method development and validation are highlighted by a critical assessment of chromatographic parameters, detection wavelengths, and mobile phases. This review provides a comprehensive reference for researchers and analysts working on dextromethorphan and sitagliptin, highlighting the importance of reliable, sensitive, and stability-indicating techniques for routine quality control and pharmacokinetic investigations. &nbsp; Dextromethorphan ; Sitagliptin ; Dextrorphan ; Bioequivalence ; Pharmacokinetics Analytical Methods in Pharmaceuticals ; ECG Monitoring and Analysis ; Advanced Chemical Sensor Technologies
Authors: Bailey Spickler
Source: KU ScholarWorks (The University of Kansas) (article, 2019-05-31)
Field: Materials Science — Materials Chemistry

Waste Heat Recovery from a Compression Ignition Engine using a Combined Diesel Particulate Filter Heat Exchanger Compression ignition (CI) engines have been a figurehead in the transportation industry for decades. However, as environmental regulations dictate increasingly strict emissions guidelines for engines, technologies must accordingly advance. To this end, this thesis describes the work of validating a combined diesel particulate filter heat exchanger (DPFHX) for CI engine exhaust waste heat recovery (WHR) in a Rankine Cycle (RC), a concept introduced in the first chapter of this thesis. The second chapter includes a comprehensive literature review, indicating the increasing prevalence of WHR in the literature. Additionally, with RC as the principal system for WHR and engine exhaust as the primary heat source, this research is exceptionally relevant. Furthermore, the primary aspects of an RC WHR system requiring individual optimization are the heat exchangers and expanders along with working fluid selection. As such, the third chapter discusses experiments to analyze and compare the DPFHX with various working fluids; thus, incorporating the literature trends of working fluid comparison and component specificity in the methodology. Consequently, in the DPFHX, water achieved a higher heat transfer rate by over 60% than the 50% by volume mixture of water and ethylene glycol, the two optimal working fluids in the apparatus without DPF cores. However, alterations made to the DPF cores’ outer diameters and lengths when installing them in the heat exchanger tubes prevented them from achieving the expected outcome (i.e., improving apparatus performance). Finally, the fourth chapter links the conclusions from this work to recommendations for future efforts to investigate DPFHXs. Diesel particulate filter ; Heat exchanger ; Particulates ; Ignition system ; Carbureted compression ignition model engine ; Compression (physics) ; Environmental science ; Waste management ; Diesel engine ; Filter (signal processing) ; Exhaust gas recirculation ; Waste heat recovery unit ; Materials science ; Automotive engineering ; Diesel fuel ; Compression ratio ; Internal combustion engine ; Mechanical engineering ; Diesel cycle ; Engineering ; Composite material ; Exhaust gas ; Chemistry Catalytic Processes in Materials Science ; Biodiesel Production and Applications ; Advanced Combustion Engine Technologies