jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ayoub Aouina | Matteo Gatti | Siyuan Chen | Shiwei Zhang | Lucia Reining
Source: Physical review. B./Physical review. B (article, 2023-05-12)
Field: Materials Science — Materials Chemistry

Accurate Kohn-Sham auxiliary system from the ground-state density of solids The Kohn-Sham (KS) system is an auxiliary system whose effective potential is unknown in most cases. It is in principle determined by the ground-state density and it has been found numerically for some low-dimensional systems by inverting the KS equations starting from a given accurate density. For solids, only approximate results are available. In this work, we determine accurate exchange-correlation (xc) potentials for Si and NaCl using the ground-state densities obtained from auxiliary field quantum Monte Carlo calculations. We show that these xc potentials can be rationalized as an ensemble of a few local functions of the density, whose form depends on the specific environment and can be well characterized by the gradient of the density and the local kinetic energy density. The KS band structure can be obtained with high accuracy. The true KS band gap turns out to be larger than the prediction of the local density approximation, but significantly smaller than the measurable photoemission gap, which confirms previous estimates. Finally, our findings show that the conjecture that very different xc potentials can lead to very similar densities and other KS observables is true also in solids, which questions the meaning of details of the potentials and, at the same time, confirms the stability of the KS system. Kohn–Sham equations ; Ground state ; Physics ; State (computer science) ; Density functional theory ; Mathematics ; Atomic physics ; Quantum mechanics ; Algorithm Thermal Expansion and Ionic Conductivity ; Advanced Chemical Physics Studies ; Luminescence Properties of Advanced Materials
Authors: Н. И. Черкашина | Z. V. Pavlenko | Dar’ya Sergeyevna Matveenko | S. N. Domarev | Dar’ya Vasil’yevna Pushkarskaya | D. A. Ryzhikh
Source: ChemEngineering (article, 2023-04-18)
Field: Materials Science — General Materials Science

Synthesis and Characteristics of Composite Material with a Plant-Based Filler The article presents the results of synthesis of polymeric composite material based on epoxy binder and plant-based filler. Pre-dried and powdered wheat straw was used as a plant-based filler. The wheat straw content in the composite varied from 10 to 50 wt.%. Thermal, mechanical, and surface properties of composites depending on the wheat straw content were researched. In addition, the samples were studied for resistance to corrosive environments. The hydrophobic–hydrophilic surface balance of composites was evaluated, and their free surface energy was studied. Introduction of wheat straw in small amounts (up to 30 wt.%) increases bending strength of polymer from 18.65 ± 1.12 MPa to 22.61 ± 0.91 MPa; when the content is more than 40 wt.%, reduction of strength is observed. Even with a wheat straw powder content of 50 wt.%, the bending strength is 11.52 ± 1.03 MPa, which corresponds to the strength of the construction material. The upper limit of working temperature for the epoxy binder is 306 °C, and for the composite with the wheat straw content of 30 wt.%—264 °C. The surface of the pure polymer shows a hydrophilic character. The average value of the water wetting contact angle of the pure epoxy sample is 84.96 ± 9.03°. The introduction of 30 wt.% of wheat straw powder filler transforms the surface into hydrophobic one (average value of water wetting contact angle is 96.69 ± 5.71°). The developed composites can be applied in furniture production including tabletops or panels for floors. Future research will focus on expanding the types of plant-based fillers for polymer composites. Materials science ; Straw ; Composite material ; Wetting ; Contact angle ; Composite number ; Flexural strength ; Epoxy ; Filler (materials) ; Chemistry Material Properties and Applications ; Natural Fiber Reinforced Composites ; Advanced Theoretical and Applied Studies in Material Sciences and Geometry
Authors: Zaharaddeen Nasiru Garba | Abdurrashid Haruna | Abdulkadir Tanimu | Binta Zakari Bello | Zakariyya Uba Zango
Source: Korean Journal of Chemical Engineering (article, 2023-05-18)
Field: Materials Science — Biomaterials

Recent progress in the preparation, characterization, and applications of modified halloysite nanotubes as adsorbents for wastewater treatment Halloysite ; Materials science ; Adsorption ; Chemical engineering ; Nanotechnology ; Wastewater ; Carbonization ; Characterization (materials science) ; Specific surface area ; Catalysis ; Waste management ; Organic chemistry ; Chemistry ; Composite material Clay minerals and soil interactions ; Iron oxide chemistry and applications ; Layered Double Hydroxides Synthesis and Applications
Authors: Ryan Leeming | Tariq Mahmud | Kevin J. Roberts | Neil George | Jennifer Webb | Elena Simone | Cameron J. Brown
Source: Industrial & Engineering Chemistry Research (article, 2023-07-03)
Field: Materials Science — Materials Chemistry

Development of a Digital Twin for the Prediction and Control of Supersaturation during Batch Cooling Crystallization Fine chemicals produced via batch crystallization with properties dependent on the crystal size distribution require precise control of supersaturation, which drives the evolution of crystal size over time. Model predictive control (MPC) of supersaturation using a mechanistic model to represent the behavior of a crystallization process requires less experimental time and resources compared with fully empirical model-based control methods. Experimental characterization of the hexamine-ethanol crystallization system was performed in order to collect the parameters required to build a one-dimensional (1D) population balance model (PBM) in gPROMS FormulatedProducts software (Siemens-PSE Ltd.). Analysis of the metastable zone width (MSZW) and a series of seeded batch cooling crystallizations informed the suitable process conditions selected for supersaturation control experiments. The gPROMS model was integrated with the control software PharmaMV (Perceptive Engineering Ltd.) to create a digital twin of the crystallizer. Simulated batch crystallizations were used to train two statistical MPC blocks, allowing for in silico supersaturation control simulations to develop an effective control strategy. In the supersaturation set-point range of 0.012-0.036, the digital twin displayed excellent performance that would require minimal controller tuning to steady out any instabilities. The MPC strategy was implemented on a physical 500 mL crystallizer, with the simulated solution concentration replaced by in situ measurements from calibrated attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Physical supersaturation control performance was slightly more unstable than the in silico tests, which is consistent with expected disturbances to the heat transfer, which were not specifically modeled in simulations. Overall, the level of supersaturation control in a real crystallizer was found to be accurate and precise enough to consider future adaptations to the MPC strategy for more advanced control objectives, such as the crystal size. Supersaturation ; Crystallization ; Process analytical technology ; Process control ; Fourier transform infrared spectroscopy ; Process (computing) ; Chemistry ; Biological system ; Process engineering ; Computer science ; Chemical engineering ; Engineering Crystallization and Solubility Studies ; Process Optimization and Integration ; Chemical and Physical Properties in Aqueous Solutions
Authors: Chunsheng Yan | Yuwei Chen | Haima Yang | Eero Ahokas
Source: Review of Scientific Instruments (article, 2023-08-01)
Field: Chemistry — Spectroscopy

Optical spectrum analyzers and typical applications in astronomy and remote sensing Scientists are increasingly relying on astronomical and remote sensing technologies to gain deeper insights into the Earth and the universe. In these fields, the optical spectrum analyzer (OSA) or spectrometer plays a pivotal role. This Review offers a comprehensive overview of the fundamental principles, key parameters, and applications of various branches of traditional OSAs, including prisms, gratings, interferometers, tunable filters, and reconstructive spectrometers. We specifically focus on their latest major applications in astronomy and remote sensing. Additionally, we present a mathematical model of the generalized reconstructive spectrometer and provide a summary of its principles pertaining to spectral mapping, reconstruction, and imaging. Despite its limited aperture and étendue, the reconstructive spectrometer holds great potential for future use in astronomy and remote sensing due to its compact size and exceptional ultrahigh spectral resolution. Spectrometer ; Astronomical interferometer ; Spectral resolution ; Remote sensing ; Interferometry ; Physics ; Optics ; Aperture (computer memory) ; Computer science ; Electromagnetic spectrum ; Astronomy ; Spectral line ; Geology ; Acoustics Spectroscopy and Laser Applications ; Atmospheric Ozone and Climate ; Optical Polarization and Ellipsometry
Authors: Petteri A. Vainikka | ‪Siewert J. Marrink
Source: Journal of Chemical Theory and Computation (article, 2023-01-10)
Field: Chemistry — Organic Chemistry

Martini 3 Coarse-Grained Model for Second-Generation Unidirectional Molecular Motors and Switches Artificial molecular motors (MMs) and switches (MSs), capable of undergoing unidirectional rotation or switching under the appropriate stimuli, are being utilized in multiple complex and chemically diverse environments. Although thorough theoretical work utilizing QM and QM/MM methods have mapped out many of the critical properties of MSs and MMs, as the experimental setups become more complex and ambitious, there is an ever increasing need to study the behavior and dynamics of these molecules as they interact with their environment. To this end, we have parametrized two coarse-grained (CG) models of commonly used MMs and a model for an oxindole-based MS, which can be used to study the ground state behavior of MMs and MSs in large simulations for significantly longer periods of time. We also propose methods to perturb these systems which can allow users to approximate how such systems would respond to MMs rotating or the MSs switching. Computer science ; Work (physics) ; Molecular motor ; Rotation (mathematics) ; Molecular switch ; Biological system ; Artificial intelligence ; Physics ; Nanotechnology ; Molecule ; Materials science ; Biology Supramolecular Chemistry and Complexes ; Advanced NMR Techniques and Applications ; Magnetism in coordination complexes
Authors: Iulia-Florentina Darie | Stefan R. Anton | Mirela Praisler
Source: Inventions (article, 2023-03-13)
Field: Chemistry — Analytical Chemistry

Machine Learning Systems Detecting Illicit Drugs Based on Their ATR-FTIR Spectra We present a comparative study aiming to determine the most efficient multivariate model screening for the main drugs of abuse based on their ATR-FTIR spectra. A preliminary statistical analysis of selected spectra data extracted from the public SWGDRUG IR Library was first performed. The results corroborated those of an exploratory analysis that was based on several dimensionality reduction methods, i.e., Principal Component Analysis (PCA), Independent Component Analysis (ICA), and autoencoders. Then, several machine learning methods, i.e., Support Vector Machines (SVM), eXtreme Gradient Boosting (XGB), Random Forest, Gradient Boosting, and K-Nearest Neighbors (KNN), were used to assign the drug class membership. In order to account for the stochastic nature of these machine learning methods, both models were evaluated 10 times on a randomly distributed subset of the whole SWGDRUG IR Library, and the results were compared in detail. Finally, their performance in assigning the class identity of three classes of drugs of abuse, i.e., hallucinogenic (2C-x, DOx, and NBOMe) amphetamines, cannabinoids, and opioids, were compared based on confusion matrices and various classification parameters, such as balanced accuracy, sensitivity, and specificity. The advantages of each of the illicit drug-detecting systems and their potential as forensic screening tools used in field scenarios are also discussed. Principal component analysis ; Artificial intelligence ; Support vector machine ; Random forest ; Boosting (machine learning) ; Machine learning ; Computer science ; Pattern recognition (psychology) ; Dimensionality reduction ; Independent component analysis Spectroscopy and Chemometric Analyses ; Metabolomics and Mass Spectrometry Studies ; Forensic Toxicology and Drug Analysis
Authors: Muhammad Rizwan Khan | Harshan Reddy Gopidi | Oleksandr I. Malyi
Source: Applied Physics Letters (article, 2023-08-07)
Field: Materials Science — Materials Chemistry

Optical properties and electronic structures of intrinsic gapped metals: Inverse materials design principles for transparent conductors Traditional solid-state physics has long correlated the optical properties of materials with their electronic structures. However, recent discoveries of intrinsic gapped metals have challenged this classical view. Gapped metals possess electronic properties distinct from both metals and insulators, with a large concentration of free carriers without any intentional doping and an internal bandgap. This unique electronic structure makes gapped metals potentially superior to materials designed by intentional doping of the wide bandgap insulators. Despite their promising applications, such as transparent conductors, designing gapped metals for specific purposes remains challenging due to the lack of understanding of the correlation between their electronic band structures and optical properties. This study focuses on representative examples of gapped metals and demonstrates the cases of (i) gapped metals (e.g., CaN2) with strong intraband absorption in the visible range, (ii) gapped metals (e.g., SrNbO3) with strong interband absorption in the visible range, and (iii) gapped metals (e.g., Sr5Nb5O17) that are potential transparent conductors. We explore the complexity of identifying potential gapped metals for transparent conductors and propose inverse materials design principles for discovering next-generation transparent conductors. Electrical conductor ; Doping ; Materials science ; Electronic band ; Band gap ; Absorption (acoustics) ; Electronic structure ; Inverse ; Optoelectronics ; Condensed matter physics ; Physics ZnO doping and properties ; Electronic and Structural Properties of Oxides ; Multiferroics and related materials
Authors: Nicole Poulsen | Nils Kröger
Source: Journal of Phycology (article, 2023-07-09)
Field: Materials Science — Biomaterials

<i>Thalassiosira pseudonana</i> (<i>Cyclotella nana</i>) (Hustedt) Hasle et Heimdal (Bacillariophyceae): A genetically tractable model organism for studying diatom biology, including biological silica formation Abstract In 2004, Thalassiosira pseudonana was the first eukaryotic marine alga to have its genome sequenced. Since then, this species has quickly emerged as a valuable model species for investigating the molecular underpinnings of essentially all aspects of diatom life, particularly bio‐morphogenesis of the cell wall. An important prerequisite for the model status of T. pseudonana is the ongoing development of increasingly precise tools to study the function of gene networks and their encoded proteins in vivo. Here, we briefly review the current toolbox for genetic manipulation, highlight specific examples of its application in studying diatom metabolism, and provide a peek into the role of diatoms in the emerging field of silica biotechnology. Thalassiosira pseudonana ; Diatom ; Biology ; Organism ; Model organism ; Frustule ; Algae ; Botany ; Computational biology ; Gene ; Evolutionary biology ; Ecology ; Genetics ; Phytoplankton ; Nutrient Diatoms and Algae Research ; Microbial Community Ecology and Physiology ; Protist diversity and phylogeny
Authors: Mikhail Elyashberg | Sriram Tyagarajan | Mihir Mandal | Alexei V. Buevich
Source: Molecules (article, 2023-04-28)
Field: Chemistry — Spectroscopy

Enhancing Efficiency of Natural Product Structure Revision: Leveraging CASE and DFT over Total Synthesis Natural products remain one of the major sources of coveted, biologically active compounds. Each isolated compound undergoes biological testing, and its structure is usually established using a set of spectroscopic techniques (NMR, MS, UV-IR, ECD, VCD, etc.). However, the number of erroneously determined structures remains noticeable. Structure revisions are very costly, as they usually require extensive use of spectroscopic data, computational chemistry, and total synthesis. The cost is particularly high when a biologically active compound is resynthesized and the product is inactive because its structure is wrong and remains unknown. In this paper, we propose using Computer-Assisted Structure Elucidation (CASE) and Density Functional Theory (DFT) methods as tools for preventive verification of the originally proposed structure, and elucidation of the correct structure if the original structure is deemed to be incorrect. We examined twelve real cases in which structure revisions of natural products were performed using total synthesis, and we showed that in each of these cases, time-consuming total synthesis could have been avoided if CASE and DFT had been applied. In all described cases, the correct structures were established within minutes of using the originally published NMR and MS data, which were sometimes incomplete or had typos. Total synthesis ; Natural product ; Density functional theory ; Chemistry ; Computer science ; Computational chemistry ; Biochemical engineering ; Stereochemistry Molecular spectroscopy and chirality ; Microbial Natural Products and Biosynthesis ; Plant biochemistry and biosynthesis
Authors: Aris E. Giannakas | Vassilios K. Karabagias | Dimitrios Moschovas | Areti Leontiou | Ioannis K. Karabagias | Stavros Georgopoulos | Andreas Karydis‐Messinis | Konstantinos Zaharioudakis | Νικόλαος Δ. Ανδρίτσος | George Kehayias | Apostolos Avgeropoulos | Charalampos Proestos | Constantinos E. Salmas
Source: Foods (article, 2023-07-03)
Field: Materials Science — Biomaterials

Thymol@activated Carbon Nanohybrid for Low-Density Polyethylene-Based Active Packaging Films for Pork Fillets’ Shelf-Life Extension Τhe replacement of food packaging additives and preservatives with bio-based antioxidant/antibacterial compounds has been a common practice in recent years following the trend of bioeconomy and nanotechnology. Such bio-additives are often enclosed in nanocarriers for a controlled release process. Following this trend in this work, a thymol (TO)-rich activated carbon (AC) nanohybrid was prepared and characterized physicochemically with various techniques. This TO@AC nanohybrid, along with the pure activated carbon, was extruded with low-density polyethylene (LDPE) to develop novel active packaging films. The codenames used in this paper were LDPE/xTO@AC and LDPE/xAC for the nanohybrid and the pure activated carbon, respectively. X-ray diffractometry, Fourier-transform infrared spectroscopy, and scanning electron microscopy measurements showed high dispersity of both the TO@AC nanohybrid and the pure AC in the LDPE matrix, resulting in enhanced mechanical properties. The active film with 15 wt.% of the TO@AC nanohybrid (LDPE/15TO@AC) exhibited a 230% higher water/vapor barrier and 1928% lower oxygen permeability than the pure LDPE film. For this active film, the highest antioxidant activity referred to the DPPH assay (44.4%), the lowest thymol release rate (k<sub>2</sub> ≈ 1.5 s<sup>-1</sup>), and the highest antibacterial activity were recorded, resulting in a 2-day extension of fresh pork fillets' shelf-life. Low-density polyethylene ; Active packaging ; Polyethylene ; Shelf life ; Materials science ; Food packaging ; Chemical engineering ; Thymol ; DPPH ; Chemistry ; Fourier transform infrared spectroscopy ; Antioxidant ; Food science ; Composite material ; Organic chemistry ; Essential oil Nanocomposite Films for Food Packaging ; biodegradable polymer synthesis and properties ; Electrospun Nanofibers in Biomedical Applications
Authors: Ning Yang | Cédric Guerin | Ninel Kokanyan | Patrick Perré
Source: Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy (article, 2023-09-03)
Field: Chemistry — Analytical Chemistry

Raman spectroscopy applied to online monitoring of a bioreactor: Tackling the limit of detection Partial least squares regression ; Principal component analysis ; Chemistry ; Outlier ; Cross-validation ; Multivariate statistics ; Calibration ; Detection limit ; Biological system ; Mean squared error ; Raman spectroscopy ; Chemometrics ; Matrix (chemical analysis) ; Analytical Chemistry (journal) ; Artificial intelligence ; Statistics ; Chromatography ; Computer science ; Mathematics Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Mineral Processing and Grinding
Authors: Haitao Bai | Xing Cui | Rui Wang | Naixin Lv | Xupeng Yang | Ruixuan Li | Yun Ma
Source: Coatings (article, 2023-04-23)
Field: Materials Science — Materials Chemistry

Effect of Surface Roughness on Static Corrosion Behavior of J55 Carbon Steel in CO2-Containing Geothermal Water at 65 °C The influence of surface roughness on the static corrosion behavior of J55 carbon steel in CO2-containing geothermal water environment was investigated with respect to average corrosion rate, morphology, chemical composition, corrosion depth, and the cross section of corrosion products. The influence of surface roughness on the CO2 corrosion of J55 carbon steel was then proposed based on the understanding of corrosion at 65 °C. The results show that the static corrosion rate of J55 carbon steel in CO2-containing geothermal water increases with increasing surface roughness. The surface roughness of J55 carbon steel increases 5.3-fold and the CO2 corrosion rate increases by 1.4-fold under different exposure times. The static corrosion rate of J55 carbon steel in CO2-containing geothermal water changes with exposure time. The corrosion rate of J55 carbon steel decreases with the increase in exposure time, and there is little change in the corrosion rate after immersion for 2 days. At the initial stage of corrosion, the corrosion rate of J55 carbon steel was mainly affected by surface roughness. The greater the roughness, the greater the corrosion driving force and the corrosion reaction surface area and therefore the greater the corrosion rate of J55 carbon steel. After immersion for 2 days, a continuous corrosion product layer was formed on the surface of J55 carbon steel and the corrosion rate was mainly affected by the corrosion product layer. The corrosion products of J55 carbon steel are not altered by surface roughness in a CO2-containing geothermal water environment. The corrosion products of J55 carbon steel are FeCO3 and a minute amount of CaCO3. Corrosion ; Carbon steel ; Materials science ; Surface roughness ; Metallurgy ; Surface finish ; Carbon fibers ; Composite material ; Composite number Corrosion Behavior and Inhibition ; Hydrogen embrittlement and corrosion behaviors in metals ; Concrete Corrosion and Durability