jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yara A Rashed | Selamawit Ashagre Messele | Hongbo Zeng | Mohamed Gamal El‐Din
Source: Environmental Technology (article, 2019-05-03)
Field: Chemistry — Analytical Chemistry

Mesoporous carbon xerogel material for the adsorption of model naphthenic acids: structure effect and kinetics modelling The study examined the preparation, characterization and the use of carbon xerogel (CX) material for the adsorption of three model naphthenic acids (NAs); such as, heptanoic acid (HPA), 5-cyclohexanepentanoic acid (CHPA), and 5-phenylvaleric acid (PVA). CX was synthesized by sol-gel method from resorcinol and formaldehyde. The characterization results showed that CX was a mesoporous material with large surface area (573 m<sup>2</sup>/g) and high pore volume (1.55 cm<sup>3</sup>/g), which was mainly composed of carbon (93.20%) and oxygen (6.71%). Adsorption studies revealed that PVA, the NA having an aromatic ring was adsorbed more easily by CX (87 mg/g) due to <i>π</i>-<i>π</i> interactions, followed by HPA (65 mg/g) and CHPA (61 mg/g). In addition, by studying the effect of solution pH, the result confirmed that repulsion greatly hindered the adsorption of HPA onto CX at pHs above that of the pH<sub>PZC</sub> and at lower pHs attractive electrostatic forces promoted adsorption. Adsorption kinetics fitted the pseudo-first-order model, which suggested that physisorption was most likely the means of adsorption. For the intraparticle diffusion model, the rate of film diffusion was higher than the rate of pore diffusion for each model compound regardless of their structure. Accordingly, this confirmed that pore diffusion was the rate-limiting step, although film diffusion still maintained a significant role in the rate of diffusion. In general, CX exhibited excellent adsorption performance due to its highly mesoporous character so it could be used as a passive treatment method in tailing ponds for removal of organic matters. Mesoporous material ; Adsorption ; Kinetics ; Carbon fibers ; Activated carbon ; Chemistry ; Chemical engineering ; Materials science ; Catalysis ; Organic chemistry ; Engineering ; Composite material Petroleum Processing and Analysis ; Hydrocarbon exploration and reservoir analysis ; Enhanced Oil Recovery Techniques
Authors: Hisham Fouad | S. A. Aboud El-Enein | Ahmed H. Orabi | Shaimaa Salah Abdulmoteleb
Source: SN Applied Sciences (article, 2019-03-06)
Field: Chemistry — Inorganic Chemistry

A new extractant impregnated resin for separation of traces of uranium and thorium followed by their spectrophotometric determination in some geological samples Thorium ; Adsorption ; Chemistry ; Uranium ; ALIZARIN RED ; Nuclear chemistry ; Metal ions in aqueous solution ; Langmuir adsorption model ; Alizarin ; Elution ; Certified reference materials ; Detection limit ; Metal ; Chromatography ; Materials science ; Metallurgy ; Organic chemistry Radioactive element chemistry and processing ; Analytical chemistry methods development ; Chemical Synthesis and Characterization
Authors: Lvshan Zhou | Tongjiang Peng | Hongjuan Sun | Xiaogang Guo | Dong Fu
Source: Minerals (article, 2019-04-25)
Field: Materials Science — Biomaterials

The Characterization and Amoxicillin Adsorption Activity of Mesopore CaCO3 Microparticles Prepared Using Rape Flower Pollen A precipitation reaction method was employed to prepare mesopore calcium carbonate (CaCO3) using rape flower pollen as the template. CaCO3 adsorbent was characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Brunner−Emmet−Teller measurements (BET). The equilibrium adsorption data on amoxicillin were explained using Langmuir, Freundlich, and Temkin adsorption isotherm models. The pseudo-first order, second order, pseudo-second order, and intra-particle diffusion kinetic models were used to explore adsorption kinetics. Equilibrium adsorption of as-prepared CaCO3 was better depicted using the Langmuir adsorption model with an R2 of 0.9948. The separation factor (RL) was found to be in the range of 0 &lt; RL &lt; 1, indicating the favorable adsorption of amoxicillin. The adsorption capacity of mesopore CaCO3 reached 13.49 mg·g−1 in 0.2 g∙L−1 amoxicillin solution. The values of adsorption thermodynamic parameters (ΔHθ, ΔSθ, ΔGθ) were obtained. In addition, the adsorption process turned out to be endothermic and spontaneous for the CaCO3 product at 298 K, 308 K, and 318 K. Adsorption ; Endothermic process ; Freundlich equation ; Mesoporous material ; Langmuir ; Langmuir adsorption model ; Materials science ; Diffusion ; Nuclear chemistry ; Chemical engineering ; Chemistry ; Organic chemistry ; Thermodynamics ; Catalysis Calcium Carbonate Crystallization and Inhibition ; Adsorption and biosorption for pollutant removal ; Polymer Surface Interaction Studies
Authors: Huiyan Piao | Myung Hun Kim | Meiling Cui | Goeun Choi | Jin‐Ho Choy
Source: Journal of Korean Medical Science (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Alendronate-Anionic Clay Nanohybrid for Enhanced Osteogenic Proliferation and Differentiation The present AL-LDH could be considered as a promising DDS for improving efficacy of AL. Alkaline phosphatase ; Intercalation (chemistry) ; Hydroxide ; Drug delivery ; Chemistry ; Nuclear chemistry ; Fourier transform infrared spectroscopy ; Transmission electron microscopy ; Nanoparticle ; Cell growth ; In vitro ; Ion exchange ; Viability assay ; Biophysics ; Materials science ; Chemical engineering ; Nanotechnology ; Biochemistry ; Inorganic chemistry ; Ion ; Organic chemistry ; Enzyme ; Biology Layered Double Hydroxides Synthesis and Applications ; Bone Tissue Engineering Materials ; Bone health and treatments
Authors: Simone Ciarella | Wouter G. Ellenbroek
Source: Coatings (article, 2019-02-12)
Field: Materials Science — Polymers and Plastics

Swap-Driven Self-Adhesion and Healing of Vitrimers Vitrimers are covalent network materials, comparable in structure to classical thermosets. Unlike normal thermosets, they possess a chemical bond swap mechanism that makes their structure dynamic and suitable for activated welding and even autonomous self-healing. The central question in designing such materials is the trade-off between autonomy and material stability: the swap mechanism facilitates the healing, but it also facilitates creep, which makes the perfectly stable self-healing solid a hard goal to reach. Here, we address this question for the case of self-healing vitrimers made from star polymers. Using coarse-grained molecular dynamics simulations, we studied the adhesion of two vitrimer samples and found that they bond together on timescales that are much shorter than the stress relaxation time. We showed that the swap mechanism allows the star polymers to diffuse through the material through coordinated swap events, but the healing process is much faster and does not depend on this mobility. Swap (finance) ; Self-healing ; Creep ; Materials science ; Polymer ; Stress relaxation ; Chemical physics ; Composite material ; Molecular dynamics ; Computer science ; Nanotechnology ; Chemistry ; Computational chemistry Polymer composites and self-healing ; Advanced Polymer Synthesis and Characterization ; Polydiacetylene-based materials and applications
Authors: Samuel Chen | Iain D. Boyd
Source: Journal of the American Ceramic Society (article, 2019-01-06)
Field: Materials Science — Ceramics and Composites

Chemical equilibrium analysis of silicon carbide oxidation in oxygen and air Abstract Due to their refractory nature and oxidation resistance, Ultra‐High Temperature Ceramic materials, including silicon carbide, are of interest in hypersonic aerospace applications. To analyze the thermodynamic behavior of silicon carbide during transition between passive and active oxidation states, chemical equilibrium calculations are performed. The predicted oxygen pressures for passive‐to‐active transition show improved agreement up to an order of magnitude with experimental transition data in the literature, compared with Wagner's model. Both oxygen and air environments are examined, and a 3% difference in transition temperature is observed. Material response analysis demonstrates that a surface temperature jump occurs during thermal oxidation of silicon carbide, corresponding to passive‐to‐active transition. Silicon carbide ; Materials science ; Oxygen ; Silicon ; Ceramic ; Carbide ; Transition temperature ; Thermodynamics ; Chemical engineering ; Chemistry ; Metallurgy ; Condensed matter physics ; Organic chemistry Advanced ceramic materials synthesis ; Energetic Materials and Combustion ; Thermal properties of materials
Authors: Natalia A. Wojas | Agne Swerin | Viveca Wallqvist | Mikael Järn | Joachim Schoelkopf | Patrick Gane | Per M. Claesson
Source: Journal of Colloid and Interface Science (article, 2019-01-14)
Field: Materials Science — Biomaterials

Iceland spar calcite: Humidity and time effects on surface properties and their reversibility Understanding the complex and dynamic nature of calcite surfaces under ambient conditions is important for optimizing industrial applications. It is essential to identify processes, their reversibility, and the relevant properties of CaCO<sub>3</sub> solid-liquid and solid-gas interfaces under different environmental conditions, such as at increased relative humidity (RH). This work elucidates changes in surface properties on freshly cleaved calcite (topography, wettability and surface forces) as a function of time (≤28 h) at controlled humidity (≤3-95 %RH) and temperature (25.5 °C), evaluated with atomic force microscopy (AFM) and contact angle techniques. In the presence of humidity, the wettability decreased, liquid water capillary forces dominated over van der Waals forces, and surface domains, such as hillocks, height about 7.0 Å, and trenches, depth about -3.5 Å, appeared and grew primarily in lateral dimensions. Hillocks demonstrated lower adhesion and higher deformation in AFM experiments. We propose that the growing surface domains were formed by ion dissolution and diffusion followed by formation of hydrated salt of CaCO<sub>3</sub>. Upon drying, the height of the hillocks decreased by about 50% suggesting their alteration into dehydrated or less hydrated CaCO<sub>3</sub>. However, the process was not entirely reversible and crystallization of new domains continued at a reduced rate. Hillock ; Calcite ; Wetting ; Dissolution ; Humidity ; Relative humidity ; Chemistry ; Contact angle ; Chemical engineering ; van der Waals force ; Supersaturation ; Crystallization ; Diffusion ; Adhesion ; Mineralogy ; Chemical physics ; Materials science ; Composite material ; Thermodynamics ; Physical chemistry ; Molecule Calcium Carbonate Crystallization and Inhibition ; Minerals Flotation and Separation Techniques ; Building materials and conservation
Authors: Mohammed Mujahid Alam | Ahmed T. Mubarak | Mohammed A. Assiri | Sarfaraz Ahmed | Ahmed M. Fouda
Source: BMC Chemistry (article, 2019-03-28)
Field: Chemistry — Organic Chemistry

A facile and efficient synthesis of 1,8-dioxodecahydroacridines derivatives catalyzed by cobalt–alanine metal complex under aqueous ethanol media A facile and convenient method for the synthesis of acridines and its derivatives was developed through one-pot, three-component condensation reaction of aromatic aldehydes, 5,5-dimethyl-1,3-cyclohexanedione, aryl amines or ammonium acetates in the presence of a catalytic amount of cobalt-alanine metal complex using aqueous ethanol as a reaction medium is reported. The present described novel methodology offers several advantages over the traditional methods reported in the literature, such as mild reaction conditions, inexpensive catalyst, short reaction times, excellent yields of products, simplicity and easy workup are the advantages of this procedure. Catalysis ; Cobalt ; Aqueous medium ; Chemistry ; Ethanol ; Aqueous solution ; Aryl ; Ammonium acetate ; Condensation reaction ; Metal ; Alanine ; Organic chemistry ; Combinatorial chemistry ; Reaction conditions ; Amino acid Multicomponent Synthesis of Heterocycles ; Synthesis and Biological Evaluation ; Cancer therapeutics and mechanisms
Authors: Keishu Utimula | Tom Ichibha | Ryo Maezono | Kenta Hongo
Source: Chemistry of Materials (article, 2019-06-05)
Field: Materials Science — Materials Chemistry

Ab Initio Search of Polymer Crystals with High Thermal Conductivity Lattice thermal conductivities (LTC) for a subset of polymer crystals from the Polymer Genome Library were investigated to explore high LTC polymer systems. We employed a first-principles approach to evaluating phonon lifetimes within the third-order perturbation theory combined with density functional theory, and then solved the linearized Boltzmann transport equation with single-mode relaxation time approximated by the computed lifetime. Typical high LTC polymer systems, polyethylene (PE) crystal and fiber, were benchmarked, which is reasonably consistent with previous references, validating our approach. We then applied it to not only typical polymer crystals, but also some selected ones having structural similarities to PE. Among the latter crystals, we discovered that beta phase of Poly(vinylidenesurely fluoride) (PVF-$\beta$) crystal has higher LTC than PE at low temperature. Our detailed mode analysis revealed that the phonon lifetime of PVF-$\beta$ is more locally distributed around lower frequency modes and four-times larger than that of PE. It was also found from a simple data analysis that the LTC relatively correlates with curvature of energy-volume plot. The curvature would be used as a descriptor for further exploration of high LTC polymer crystals by means of a data-driven approach beyond human-based one. Thermal conductivity ; Ab initio ; Materials science ; Polymer ; Conductivity ; Ab initio quantum chemistry methods ; Chemical physics ; Physical chemistry ; Chemistry ; Molecule ; Composite material ; Organic chemistry Machine Learning in Materials Science ; Thermal properties of materials ; Advanced Memory and Neural Computing
Authors: Nidhi Sharma | Vineeta Singh | Asheesh Kumar Pandey | Bhartendu Nath Mishra | Maria Kulsoom | Nandita Dasgupta | Saif Khan | Hesham A. El-Enshasy | Shafiul Haque
Source: Biomolecules (article, 2019-11-21)
Field: Materials Science — Materials Chemistry

Preparation and Evaluation of the ZnO NP–Ampicillin/Sulbactam Nanoantibiotic: Optimization of Formulation Variables Using RSM Coupled GA Method and Antibacterial Activities Nanoparticles (NPs) possessing antibacterial activity represent an effective way of overcoming bacterial resistance. In the present work, we report a novel formulation of a nanoantibiotic formed using Ampicillin/sulbactam (Ams) and a zinc oxide nanoparticle (ZnO NP). 'ZnO NP-Ams' nanoantibiotic formulation is optimized using response surface methodology coupled genetic algorithm approach. The optimized formulation of nanoantibiotic (ZnO NP: 49.9 μg/mL; Ams: 33.6 μg/mL; incubation time: 27 h) demonstrated 15% enhanced activity compared to the unoptimized formulation against <i>K. pneumoniae</i>. The reactive oxygen species (ROS) generation was directly proportional to the interaction time of nanoantibiotic and <i>K. pneumoniae</i> after the initial lag phase of ~18 h as evident from 2'-7'-Dichlorodihydrofluorescein diacetate assay. A low minimum inhibitory concentration (6.25 μg/mL) of nanoantibiotic formulation reveals that even a low concentration of nanoantibiotic can prove to be effective against <i>K. pneumoniae.</i> The importance of nanoantibiotic formulation is also evident by the fact that the 100 μg/mL of Ams and 25 µg of ZnO NP was required individually to inhibit the growth of <i>K. pneumonia</i>, whereas only 6.25 μg/mL of optimized nanoantibiotic formulation (ZnO NP and Ams in the ratio of 49.9: 33.6 in μg/mL and conjugation time of 27 h) was needed for the same. Sulbactam ; Ampicillin ; Minimum inhibitory concentration ; Response surface methodology ; Nanoparticle ; Chemistry ; Antibacterial activity ; Zinc ; Materials science ; Chromatography ; Nanotechnology ; Antibiotic resistance ; Antibiotics ; Bacteria ; Biochemistry ; Biology Nanoparticles: synthesis and applications ; Pharmaceutical and Antibiotic Environmental Impacts ; Chemical and Physical Properties in Aqueous Solutions
Authors: S. Vasilchenko | H. Tran | D. Mondelain | S. Kassi | A. Campargue
Source: Journal of Quantitative Spectroscopy and Radiative Transfer (article, 2019-06-23)
Field: Chemistry — Spectroscopy

Accurate absorption spectroscopy of water vapor near 1.64 µm in support of the MEthane Remote LIdar missioN (MERLIN) Water vapor ; Methane ; Nadir ; Spectral line ; Absorption (acoustics) ; Absorption spectroscopy ; Spectrometer ; Materials science ; Lidar ; Remote sensing ; Analytical Chemistry (journal) ; Environmental science ; Optics ; Chemistry ; Meteorology ; Physics ; Geology Spectroscopy and Laser Applications ; Atmospheric and Environmental Gas Dynamics ; Atmospheric Ozone and Climate
Authors: Patricia Al-Alam | Gilles Pernot | Mykola Isaiev | David Lacroix | Mélanie de Vos | Nicolas Stein | David Osenberg | Laëtitia Philippe
Source: Physical review. B./Physical review. B (article, 2019-09-03)
Field: Materials Science — Materials Chemistry

Lattice thermal conductivity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Bi</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> and SnSe using Debye-Callaway and Monte Carlo phonon transport modeling: Application to nanofilms and nanowires The present work addresses the problem of thermal conductivity simulation in ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ and SnSe thermoelectric nanostructures. It first details phonon lifetime calculation in both thermoelectric compounds assuming polynomial dispersion properties and the Debye-Callaway model for the relaxation-time approximation. For both materials, distinct crystallographic directions are considered, i.e., $\mathrm{\ensuremath{\Gamma}}\ensuremath{-}Z$ (trigonal axis) and $\mathrm{\ensuremath{\Gamma}}\ensuremath{-}X$ (basal plane) for ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ and $\mathrm{\ensuremath{\Gamma}}\ensuremath{-}X$ ($a$ axis), $\mathrm{\ensuremath{\Gamma}}\ensuremath{-}Y$ ($b$ axis), and $\mathrm{\ensuremath{\Gamma}}\ensuremath{-}Z$ ($c$ axis) for SnSe. On this basis, the lifetime model is parametrized and bulk thermal conductivity is computed through the resolution of the phonon Boltzmann transport equation with a Monte Carlo method. Gr\"uneisen parameter and mass-disorder lifetime are adjusted to fit experimental temperature dependence. The second part of the study addresses the calculation of thermal conductivity for these two thermoelectric materials in the case of thin films (cross-plane case) and nanowires. The main goals of this work are to provide a fully parametric description of heat transport in ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ and SnSe nanofilms and nanowires showing reliable behavior on an extended size range, from 20 nm to $2\phantom{\rule{0.0pt}{0ex}}\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$, and large temperature range (100--500 K for ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$; 200--800 K for SnSe). Comparisons to bulk thermal conductivity calculations and measurements as well as to recent investigations on nanowires, demonstrate the effectiveness of the proposed methodology to deal with nanostructured ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ and SnSe. Thermal conductivity ; Physics ; Condensed matter physics ; Thermoelectric effect ; Materials science ; Thermodynamics Advanced Thermoelectric Materials and Devices ; Thermal properties of materials ; Thermal Radiation and Cooling Technologies
Authors: Norman E. Davey | M. Madan Babu | Martin Blackledge | Alan Bridge | Salvador Capella-Gutiérrez | Zsuzsanna Dosztányi | Rachel Drysdale | Richard J. Edwards | Arne Elofsson | Isabella C. Felli | Toby J. Gibson | Aleksandras Gutmanas | John M. Hancock | Jennifer Harrow | Desmond G. Higgins | Cy M. Jeffries | Philippe Le Mercier | Bálint Mészáros | Marco Necci | Cédric Notredame | Sandra Orchard | Christos Ouzounis | Rita Pancsa | Elena Papaleo | Roberta Pierattelli | Damiano Piovesan | Vasilis J. Promponas | Patrick Ruch | Gabriella Rustici | Pedro Romero | Sirarat Sarntivijai | Gary Saunders | Benjamin Schuler | Malvika Sharan | Denis C. Shields | Joel L. Sussman | Jonathan Tedds | Péter Tompa | Michael Turewicz | Jiřı́ Vondrášek | Wim Vranken | B.A. Wallace | Kanin Wichapong | Silvio C. E. Tosatto
Source: F1000Research (preprint, 2019-10-15)
Field: Chemistry — Spectroscopy

An intrinsically disordered proteins community for ELIXIR Intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) are now recognised as major determinants in cellular regulation. This white paper presents a roadmap for future e-infrastructure developments in the field of IDP research within the ELIXIR framework. The goal of these developments is to drive the creation of high-quality tools and resources to support the identification, analysis and functional characterisation of IDPs. The roadmap is the result of a workshop titled "An intrinsically disordered protein user community proposal for ELIXIR" held at the University of Padua. The workshop, and further consultation with the members of the wider IDP community, identified the key priority areas for the roadmap including the development of standards for data annotation, storage and dissemination; integration of IDP data into the ELIXIR Core Data Resources; and the creation of benchmarking criteria for IDP-related software. Here, we discuss these areas of priority, how they can be implemented in cooperation with the ELIXIR platforms, and their connections to existing ELIXIR Communities and international consortia. The article provides a preliminary blueprint for an IDP Community in ELIXIR and is an appeal to identify and involve new stakeholders. Elixir (programming language) ; Blueprint ; Identification (biology) ; Intrinsically disordered proteins ; Benchmarking ; Data science ; Political science ; Computer science ; Knowledge management ; Engineering ; Business ; Biology Advanced Proteomics Techniques and Applications ; Protein Structure and Dynamics ; Bioinformatics and Genomic Networks
Authors: Angus Voice | Gary Tresadern | Herman van Vlijmen | Adrian J. Mulholland
Source: Journal of Chemical Information and Modeling (article, 2019-09-09)
Field: Chemistry — Organic Chemistry

Limitations of Ligand-Only Approaches for Predicting the Reactivity of Covalent Inhibitors Covalent inhibition has undergone a resurgence and is an important modern-day drug design and chemical biology approach. To avoid off-target interactions and to fine-tune reactivity, the ability to accurately predict reactivity is vitally important for the design and development of safer and more effective covalent drugs. Several ligand-only metrics have been proposed that promise quick and simple ways of determining covalent reactivity. In particular, we examine proton affinity and reaction energies calculated with the density functional B3LYP-D3/6-311+G**//B3LYP-D3/6-31G* method to assess the reactivity of a series of α,β-unsaturated carbonyl compounds that form covalent adducts with cysteine. We demonstrate that while these metrics correlate well with experiment for a diverse range of small reactive molecules these approaches fail for predicting the reactivity of drug-like compounds. We conclude that ligand-only metrics such as proton affinity and reaction energies do not capture determinants of reactivity in situ and fail to account for important factors such as conformation, solvation, and intermolecular interactions. Reactivity (psychology) ; Covalent bond ; Chemistry ; Ligand (biochemistry) ; Computational chemistry ; Adduct ; Solvation ; Combinatorial chemistry ; Proton affinity ; Proton ; Molecule ; Organic chemistry ; Biochemistry ; Ion ; Receptor Click Chemistry and Applications ; Computational Drug Discovery Methods ; Chemical Synthesis and Analysis