jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yoshihide Sawada | Koji Morikawa | Mikiya Fujii
Source: arXiv (Cornell University) (preprint, 2019-10-25)
Field: Materials Science — Materials Chemistry

Study of Deep Generative Models for Inorganic Chemical Compositions Generative models based on generative adversarial networks (GANs) and variational autoencoders (VAEs) have been widely studied in the fields of image generation, speech generation, and drug discovery, but, only a few studies have focused on the generation of inorganic materials. Such studies use the crystal structures of materials, but material researchers rarely store this information. Thus, we generate chemical compositions without using crystal information. We use a conditional VAE (CondVAE) and a conditional GAN (CondGAN) and show that CondGAN using the bag-of-atom representation with physical descriptors generates better compositions than other generative models. Also, we evaluate the effectiveness of the Metropolis-Hastings-based atomic valency modification and the extrapolation performance, which is important to material discovery. Generative grammar ; Valency ; Extrapolation ; Computer science ; Generative adversarial network ; Representation (politics) ; Crystal (programming language) ; Artificial intelligence ; Generative model ; Adversarial system ; Machine learning ; Deep learning ; Pattern recognition (psychology) ; Mathematics ; Linguistics Machine Learning in Materials Science ; Topic Modeling ; Computational Drug Discovery Methods
Authors: Pankaj Rajak | Aravind Krishnamoorthy | Aiichiro Nakano | Priya Vashishta | Rajiv K. Kalia
Source: Physical review. B./Physical review. B (article, 2019-07-30)
Field: Materials Science — Materials Chemistry

Structural phase transitions in a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="normal">MoWSe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> monolayer: Molecular dynamics simulations and variational autoencoder analysis Electrical and optoelectronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) can be tuned by exploiting their structural phase transitions. Here semiconducting (2H) to metallic (1T) phase transition is investigated in a strained ${\mathrm{MoWSe}}_{2}$ monolayer using molecular dynamics (MD) simulations. Novel intermediate structures called $\ensuremath{\alpha}$ and $\ensuremath{\beta}$ are found between the 2H and 1T phases. These intermediate structures are similar to those observed in a 2D $\mathrm{Mo}{\mathrm{S}}_{2}$ by scanning transmission electron microscopy. A deep generative model, namely the variational autoencoder (VAE) trained by MD data, is used to generate novel heterostructures with $\ensuremath{\alpha}$ and $\ensuremath{\beta}$ interfaces. Quantum simulations based on density functional theory show that these heterostructures are stable and suitable for novel nanoelectronics applications. Autoencoder ; Heterojunction ; Materials science ; Phase (matter) ; Monolayer ; Crystallography ; Density functional theory ; Nanoelectronics ; Condensed matter physics ; Physics ; Machine learning ; Nanotechnology ; Computer science ; Quantum mechanics ; Chemistry ; Deep learning 2D Materials and Applications ; Machine Learning in Materials Science ; MXene and MAX Phase Materials
Authors: Mingtao Tao | Jing Liu | Suyun He | Keming Xu | Wenying Zhong
Source: Soft Matter (article, 2019-01-01)
Field: Materials Science — Biomaterials

<i>In situ</i> hydrogelation of forky peptides in prostate tissue for drug delivery Herein, we have designed and synthesized a novel forky peptide D3F3 that transforms into a hydrogel through crosslinking induced by ZIs stimuli. We have employed D3F3 as a suitable drug carrier that is conjugated with DOX. Since the concentration of zinc ions necessary for triggering gelation falls into the physiological range present in prostate tissue, while other cationic ions fail to trigger at physiological concentrations, the peptide-based drug delivery system (DDS) is injectable and would achieve prostate tissue-specific self-assembly in situ. The D3F3 hydrogels exhibited an optimal gelation time, satisfactory mechanical strength (can be enhanced after incorporation of DOX) as well as excellent thixotropic properties. The DDS reserved some DOX in the prostate 24 h after the injection, making local sustained release possible. In addition, the peptide materials demonstrated no cytotoxicity against normal fibroblast cells and no damage was observed to the prostate tissue of rats. The drug release followed a non-Fickian diffusion model, with no burst release observed. Importantly, the DOX-hydrogel system exhibited good anti-cancer efficacy when incubated with prostate cancer cells DU-145. Therefore, this study lays the groundwork for the future design of tissue-specific DDSs that are triggered by cationic ions (e.g. zinc ions), and the platform could be further developed to incorporate other potent drugs utilized in the field of prostate cancer therapy, thereby increasing their potency and reducing their side effects. In situ ; Drug delivery ; Prostate ; Doxorubicin ; Chemistry ; Materials science ; Nanotechnology ; Medicine ; Internal medicine ; Organic chemistry Supramolecular Self-Assembly in Materials ; Peptidase Inhibition and Analysis ; Dendrimers and Hyperbranched Polymers
Authors: J. Guterl | R.D. Smirnov | P.B. Snyder
Source: Nuclear Fusion (article, 2019-06-10)
Field: Materials Science — Materials Chemistry

Effects of surface processes on hydrogen outgassing from metal in desorption experiments In this study, effects of surface processes on hydrogen outgassing during desorption experiments are investigated using a standard reaction-diffusion model describing hydrogen transport, retention and desorption in material. Three mechanisms for hydrogen migration and desorption on material surface are considered: hydrogen migration from material bulk to material surface (readsorption), hydrogen migration from material surface to material bulk (reabsorption) and hydrogen desorption from material surface by molecular recombination. Three hydrogen outgassing regimes are identified: i) recombination-limited outgassing when hydrogen recombination and desorption is fast compared to hydrogen reabsorption and slow compared to hydrogen transport from material bulk onto material surface ii) reabsorption-limited outgassing when hydrogen recombination and desorption is slow compared to hydrogen reabsorption and when the effective hydrogen recombination and desorption is slow compared to hydrogen transport from material bulk onto material surface iii) bulk-limited outgassing otherwise. Regimes of hydrogen outgassing from tungsten and beryllium are estimated for various experimental conditions. Analytical expressions of the outgassing flux are then derived for each outgassing regime, and used to characterize TDS spectra obtained in TDS experiments. It is shown that TDS spectra in recombination-limited regime are skewed toward high temperature, while TDS spectra in reabsorptionlimited and bulk-limited regimes are skewed toward low temperature. Furthermore, the temperature of the desorption peak in TDS spectra is shown to decrease in recombination-limited regime and to increase in reabsorption-limited and bulk-limited regimes as the total amount of hydrogen stored in material increases. Lastly, it is observed that the effective hydrogen recombination rate measured in reabsorption-limited permeations experiments may be not be reliably used to model and predict hydrogen retention and recycling from tungsten during plasma operations in tokamak. Outgassing ; Desorption ; Hydrogen ; Thermal desorption spectroscopy ; Thermal desorption ; Materials science ; Chemisorption ; Tungsten ; Chemical physics ; Analytical Chemistry (journal) ; Chemistry ; Adsorption ; Physical chemistry ; Metallurgy Fusion materials and technologies ; Nuclear Materials and Properties ; Molten salt chemistry and electrochemical processes
Authors: Mathieu Debure | Yannick Linard | Christelle Martin | Francis Claret
Source: npj Materials Degradation (article, 2019-10-31)
Field: Materials Science — Materials Chemistry

In situ nuclear-glass corrosion under geological repository conditions Abstract Silicate glasses are durable materials but laboratory experiments reveal that elements that derive from their environment may induce high corrosion rates and reduce their capacity to confine high-level radioactive waste. This study investigates nuclear-glass corrosion in geological media using an in situ diffusion experiment and multi-component diffusion modelling. The model highlights that the pH imposed by the Callovo–Oxfordian (COx) claystone host rock supports secondary-phase precipitation and increases glass corrosion compared with pure water. Elements from the COx rock (mainly Mg and Fe) form secondary phases with Si provided by the glass, which delay the establishment of a passivating interface. The presence of elements (Mg and Fe) that sustain glass alteration does not prevent a significant decrease in the glass-alteration rate, mainly due to the limited species transport that drives system reactivity. These improvements in the understanding of glass corrosion in its environment provide further insights for predictive modelling over larger timescales and space. Corrosion ; Radioactive waste ; Diffusion ; Precipitation ; Phase (matter) ; Materials science ; In situ ; Spent nuclear fuel ; Silicate ; Silicate glass ; Metallurgy ; Mineralogy ; Geology ; Chemical engineering ; Composite material ; Chemistry ; Thermodynamics ; Nuclear chemistry Nuclear materials and radiation effects ; Glass properties and applications ; Concrete and Cement Materials Research
Authors: M. S. Hagag
Source: International Journal of Environmental & Analytical Chemistry (article, 2019-10-11)
Field: Chemistry — Inorganic Chemistry

Comparative study of fabricated composites based on phosphogypsum and Al-hydroxide for uranium separation from aqueous and waste solutions The using of phosphogypsum (known as a waste by-product of phosphoric acid production) with cheap compound alumina afforded environmental and economic aspects, as well as targeted production of promising adsorbents for uranium adsorption. Three fabricated composites based on phosphogypsum and Al-hydroxide were thermally synthesised to adsorb uranium from aqueous and wastes solution. The first one (PGA) was synthesised by mixing phosphogypsum, aluminium chloride and caustic soda at 800°C. Also, the other two composites are prepared by mixing of phosphogypsum with sodium molybdate or zirconium oxychloride to synthesis PAM and PAZ, respectively. We conducted several batches to determine the factors affecting the adsorption of uranium, including pH, initial uranium concentration, adsorbent weight, equilibrium time and interfering ions. The adsorption isotherm models were satisfactory to fit with Langmuir isotherm, exhibiting theoretical adsorption capacities of 400, 454 and 477 mg/g for composites PGA, PAM and PAZ, respectively. The adsorption studies of U in the presence of some possible interfering elements have been discussed. Elution of uranium has been achieved and optimised using 2 N of hydrochloric acid. The adsorption of uranium on the composites compatible with pseudo-second-order model, but the liquid film diffusion model and the intraparticles diffusion model were not the only limiting step. Phosphogypsum ; Adsorption ; Uranium ; Phosphoric acid ; Aqueous solution ; Hydrochloric acid ; Langmuir adsorption model ; Materials science ; Nuclear chemistry ; Langmuir ; Sodium hydroxide ; Chemistry ; Chemical engineering ; Inorganic chemistry ; Metallurgy ; Organic chemistry ; Raw material Radioactive element chemistry and processing ; Radioactivity and Radon Measurements ; Chemical Synthesis and Characterization
Authors: Biljana Koturević | Borivoj Adnadjević | Jelena R. Jovanović
Source: Green Processing and Synthesis (article, 2019-11-06)
Field: Materials Science — Materials Chemistry

The kinetics of the extraction of caffeine from guarana seed under the action of ultrasonic field with simultaneous cooling Abstract The kinetics of isothermal extraction of caffeine from guarana seed under the action of ultrasonic field with simultaneous cooling (UESC) was investigated. The isothermal kinetics curves were measured at temperatures range T = 17-58 ° C. Using the model-fitting method it was determined that the kinetics of caffeine extraction can be described by a theoretical Jander three-dimensional diffusional model. The values of the rate constant were calculated for different temperatures, as well as the kinetic parameters (activation energy ( E a ) and pre-exponential factor (ln A )). Based on the results obtained, it is concluded that the rate constants of caffeine extraction under UESC are about 2 times higher in comparison to the values obtained for the extraction in the conditions of conventional heating (CH). The activation energy of the caffeine extraction under the UESC <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mfenced> <m:mrow> <m:msub> <m:mi>E</m:mi> <m:mrow> <m:mtext>a</m:mtext> </m:mrow> </m:msub> <m:msup> <m:mspace/> <m:mrow> <m:mtext>UESC</m:mtext> </m:mrow> </m:msup> <m:mo>=</m:mo> <m:mn>19.4</m:mn> <m:mspace/> <m:mtext>kJ</m:mtext> <m:mo>⋅</m:mo> <m:mtext>mo</m:mtext> <m:mrow> <m:msup> <m:mrow> <m:mtext>l</m:mtext> </m:mrow> <m:mrow> <m:mo>−</m:mo> <m:mn>1</m:mn> </m:mrow> </m:msup> </m:mrow> </m:mrow> </m:mfenced> </m:math> $\left( E_{\text{a}}\,^{\text{UESC}}=19.4\,\text{kJ}\cdot \text{mo}{{\text{l}}^{-1}} \right)$ is lower than the values are for CH <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mfenced> <m:mrow> <m:msub> <m:mi>E</m:mi> <m:mrow> <m:mtext>a</m:mtext> </m:mrow> </m:msub> <m:msup> <m:mspace/> <m:mrow> <m:mtext>CH</m:mtext> </m:mrow> </m:msup> <m:mo>=</m:mo> <m:mn>21.8</m:mn> <m:mspace/> <m:mtext>kJ</m:mtext> <m:mo>⋅</m:mo> <m:mtext>mo</m:mtext> <m:mrow> <m:msup> <m:mrow> <m:mtext>l</m:mtext> </m:mrow> <m:mrow> <m:mo>−</m:mo> <m:mn>1</m:mn> </m:mrow> </m:msup> </m:mrow> </m:mrow> </m:mfenced> <m:mo>.</m:mo> </m:math> $\left( E_{\text{a}}\,^{\text{CH}}=21.8\,\text{kJ}\cdot \text{mo}{{\text{l}}^{-1}} \right).$ Energy consumption for UESC is four times lower than for CH conditions. It is shown that there is a linear correlation relationship between kinetic parameters obtained for UESC and CH conditions. The changes in the values of kinetic parameters are explained by the model of selective transfer of energy from the reaction system to the reactant molecules. Activation energy ; Kinetic energy ; Caffeine ; Kinetics ; Extraction (chemistry) ; Reaction rate constant ; Isothermal process ; Chemistry ; Thermodynamics ; Analytical Chemistry (journal) ; Physical chemistry ; Chromatography ; Physics Ultrasound and Cavitation Phenomena ; Microbial Inactivation Methods ; Free Radicals and Antioxidants
Authors: Mohamed E. M. Hassouna | Ragab R. Amin | Alaa A. Ahmed-Anwar | Rehab Mahmoud
Source: Egyptian Journal of Chemistry (article, 2019-06-15)
Field: Materials Science — Materials Chemistry

Efficient Removal of Oxytetracycline and Some Heavy Metals from Aqueous Solutions by Mg-Al Layered Double Hydroxide Nanomaterial Mg–Al LDH nanoparticles with nitrate intercalated anions, as an adsorbent, was prepared through coprecipitation technique of solutions of magnesium nitrate hexahydrates and aluminum nitrate (with percentage 3:1 molar ratio respectively). The nanomaterial was characterized before and after adsorption of some pollutants in wastewater by XRD, FT-IR, BET surface area, zeta potential, FESEM and HRTEM. The adsorption capability of the adsorbent was studied with regard to several pollutants in wastewater like (copper, zinc, iron, cobalt, nickel metal ions and oxytetracycline) in single solution. Various factors such as pH (3-10), dose of Mg-Al LDH ( 0.025-0.2g), concentration of metal ions (15-60 ppm) and effect of shaking time (5-120 min) were applied to optimize the removal ability of Mg-Al LDH. The adsorption efficiency of the pollutant by Mg-Al LDH was calculated, the kinetics and the isotherm of adsorption strength over the adsorbent were further studied. Adsorption ; Coprecipitation ; Zeta potential ; Chemistry ; Metal ions in aqueous solution ; Aqueous solution ; Hydroxide ; Inorganic chemistry ; Nuclear chemistry ; Magnesium ; Wastewater ; Metal hydroxide ; Zinc ; Metal ; Nanoparticle ; Materials science ; Environmental engineering ; Organic chemistry ; Nanotechnology Layered Double Hydroxides Synthesis and Applications ; Adsorption and biosorption for pollutant removal ; Chemical Synthesis and Characterization
Authors: Nady A. Fathy | Sahar M. El‐Khouly | Reham Aboelenin
Source: Egyptian Journal of Chemistry (article, 2019-05-29)
Field: Chemistry — Spectroscopy

Carbon xerogel/Carbon Nanotubes Nanohybrid Doped with Ti for Removal of Methylene Blue Dye A facile technology for decorating carbon xerogel (CX) with carbon nanotubes (CNTs) to prepare carbonaceous nanohybrid (CX-CNTs) was simultaneously implemented during carbonization of resorcinol-formaldehyde xerogel at 1123K meanwhile camphor as carbon nanotubes source is heated at 523K. Then the prepared CX-CNTs hybrid is doped with tetrabutyl orthotitanate as a titanium (Ti) precursor giving CX-CNTs-Ti nanohybrid used as an efficient photocatalyst. The morphology and textural properties of the samples were investigated using field-emission scanning electron microscope (FE-SEM), High resolution transmission electron microscopy (TEM) and N2 adsorption-desorption isotherm at 77K. The adsorption and photocatalytic properties of these samples toward methylene blue dye (MB) were performed. FE-SEM and TEM approved the formation of CNTs over the surface of CX and the developed nanohybrids have mesoporous structures. The adsorption efficiency of CX-CNTs and CX-CNTs-Ti samples was found to be 70 and 86.8% along 180 min, respectively. Under visible irradiation, the removal efficiency of CX-CNTs and CX-CNTs-Ti is enhanced to 90 and 99% at 60 min, respectively. Thus, CX-CNTs-Ti nanohybrid exhibited superior adsorptivity and photoactivity for removing MB dye as a result of the presence of Ti particles over CX-CNTs matrix. Doping CX-CNTs with Ti particles led to a decrease in the specific surface area and to enhance in both the total pore volume and amount of wider pores. Therefore, the reported CX-CNTs-Ti nanohybrid exhibits as an effective adsorbent and photocatalyst toward the removal of the MB dye from their aqueous solutions. Methylene blue ; Carbon nanotube ; Carbon fibers ; Materials science ; Doping ; Methylene ; Nanotechnology ; Chemical engineering ; Chemistry ; Organic chemistry ; Optoelectronics ; Composite material ; Catalysis ; Composite number ; Photocatalysis Aerogels and thermal insulation ; Mesoporous Materials and Catalysis ; Supercapacitor Materials and Fabrication
Authors: Han‐Sol Yun | Byeong-Gyu Yun | Hye‐Min Lee | Dae‐Yong Jeong | Wan-In Lee | Nam-Hee Cho
Source: SN Applied Sciences (article, 2019-10-10)
Field: Chemistry — Organic Chemistry

Low-temperature synthesis of nanoscale BaTiO3 powders via microwave-assisted solid-state reaction Nanocrystalline material ; Activation energy ; Materials science ; Crystallization ; Stoichiometry ; Atmospheric temperature range ; Chemical engineering ; Solid-state ; Chemistry ; Physical chemistry ; Thermodynamics ; Nanotechnology Microwave-Assisted Synthesis and Applications ; Microwave Dielectric Ceramics Synthesis ; Ferroelectric and Piezoelectric Materials
Authors: Zengxin Pan | Xin Zhang | Xinbo Wang
Source: SN Applied Sciences (article, 2019-02-18)
Field: Materials Science — Materials Chemistry

Adsorption of acid orange 10 on cross-linked porous polyimide Polyimide ; Adsorption ; Orange (colour) ; Porosity ; Chemical engineering ; Chemistry ; Materials science ; Composite material ; Organic chemistry ; Layer (electronics) ; Engineering ; Food science Covalent Organic Framework Applications ; Adsorption and biosorption for pollutant removal ; Supramolecular Self-Assembly in Materials
Authors: Nikolay Mukhin | Dmitry Chigirev | Liubov Bakhchova | A. V. Tumarkin
Source: Materials (article, 2019-09-10)
Field: Materials Science — Materials Chemistry

Microstructure and Properties of PZT Films with Different PbO Content—Ionic Mechanism of Built-In Fields Formation Experimental studies were conducted on the effects of lead oxide on the microstructure and the ferroelectric properties of lead zirconate-titanate (PZT) films obtained by the method of radio frequency (RF) magnetron sputtering of a ceramic PZT target and PbO<sub>2</sub> powder with subsequent heat treatment. It is shown that the change in ferroelectric properties of polycrystalline PZT films is attributable to their heterophase structure with impurities of lead oxide. It is also shown that, even in the original stoichiometric PZT film, under certain conditions (temperature above 580 °C, duration greater than 70 min), impurities of lead oxide may be formed. The presence of a sublayer of lead oxide leads to a denser formation of crystallization centers of the perovskite phase, resulting in a reduction of the grain size as well as the emergence of a charge on the lower interface. The formation of the perovskite structure under high-temperature annealing is accompanied by the diffusion of lead into the surface of the film. Also shown is the effect of the lead ions segregation on the formation of the self-polarized state of thin PZT films. Materials science ; Microstructure ; Lead oxide ; Ferroelectricity ; Impurity ; Perovskite (structure) ; Annealing (glass) ; Lead zirconate titanate ; Oxide ; Crystallite ; Ceramic ; Thin film ; Composite material ; Mineralogy ; Chemical engineering ; Dielectric ; Metallurgy ; Nanotechnology ; Optoelectronics Ferroelectric and Piezoelectric Materials ; Acoustic Wave Resonator Technologies ; Material Science and Thermodynamics
Authors: Bence Gajdics | János J. Tomán | H. Zapolsky | Zoltán Erdélyi | Gilles Demange
Source: Journal of Applied Physics (article, 2019-08-13)
Field: Materials Science — Materials Chemistry

A multiscale procedure based on the stochastic kinetic mean field and the phase-field models for coarsening We report a quantitative multiscale (MS) procedure based on the recently developed Stochastic Kinetic Mean Field approach (SKMF) [Erdélyi, M. Pasichnyy, V. Bezpalchuk, J. J. Tomán, B. Gajdics, and A. M. Gusak, Comput. Phys. Commun. 204, 31–37 (2016)], combined with the Phase Field model (PFM) and CALPHAD database, to study the nucleation-growth-coarsening process in alloys. The SKMF approach reproduces the nucleation and early growth of precipitates in the matrix, and the PFM then simulates the coarsening of the microstructure. To ensure the consistency of the procedure, the length and time scales of SKMF and PFM are explicitly connected. Moreover, both the effective interaction energies used in the SKMF and the free energy used in the PFM are taken from CALPHAD database. Two different implementations of the procedure are proposed. First, the postnucleation microstructure as provided by SKMF is used as the initial condition for subsequent PFM simulations. Second, only the particle size distribution and particle density are transferred to PFM, thereby giving access to bigger systems. The proposed procedure is tested in the specific case of the Ag-Cu model alloy. Nucleation ; CALPHAD ; Statistical physics ; Kinetic energy ; Microstructure ; Materials science ; Phase (matter) ; Particle (ecology) ; Consistency (knowledge bases) ; Alloy ; Field (mathematics) ; Thermodynamics ; Computer science ; Condensed matter physics ; Mathematics ; Physics ; Metallurgy ; Phase diagram ; Geology ; Discrete mathematics ; Classical mechanics ; Quantum mechanics Solidification and crystal growth phenomena ; nanoparticles nucleation surface interactions ; Aluminum Alloy Microstructure Properties