jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yiheng Zhu | Zhenqiu Ouyang | Ben Liao | Jialu Wu | Yixuan Wu | Chang‐Yu Hsieh | Tingjun Hou | Jian Wu
Source:  (article, 2023-08-01)
Field: Materials Science — Materials Chemistry

MolHF: A Hierarchical Normalizing Flow for Molecular Graph Generation Molecular de novo design is a critical yet challenging task in scientific fields, aiming to design novel molecular structures with desired property profiles. Significant progress has been made by resorting to generative models for graphs. However, limited attention is paid to hierarchical generative models, which can exploit the inherent hierarchical structure (with rich semantic information) of the molecular graphs and generate complex molecules of larger size that we shall demonstrate to be difficult for most existing models. The primary challenge to hierarchical generation is the non-differentiable issue caused by the generation of intermediate discrete coarsened graph structures. To sidestep this issue, we cast the tricky hierarchical generation problem over discrete spaces as the reverse process of hierarchical representation learning and propose MolHF, a new hierarchical flow-based model that generates molecular graphs in a coarse-to-fine manner. Specifically, MolHF first generates bonds through a multi-scale architecture, then generates atoms based on the coarsened graph structure at each scale. We demonstrate that MolHF achieves state-of-the-art performance in random generation and property optimization, implying its high capacity to model data distribution. Furthermore, MolHF is the first flow-based model that can be applied to model larger molecules (polymer) with more than 100 heavy atoms. The code and models are available at https://github.com/violet-sto/MolHF. Computer science ; Theoretical computer science ; Generative model ; Exploit ; Differentiable function ; Representation (politics) ; Graph ; Hierarchical database model ; Generative grammar ; Artificial intelligence ; Data mining ; Mathematics Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Protein Structure and Dynamics
Authors: Deyun Wang | Yongchao Su | Kang Chen
Source: The Journal of Physical Chemistry Letters (article, 2023-05-16)
Field: Chemistry — Organic Chemistry

Fast Dynamics of Difluprednate in Micelles or Swollen-Micelles Revealed by <sup>19</sup>F Nuclear Magnetic Resonance Spin Relaxation Rates Knowledge of molecular rotational dynamics is critical to interpret solution nuclear magnetic resonance (NMR) spectroscopy. The observation of sharp solute NMR signals in micelles contradicted the surfactant viscosity effects noted in the Stokes-Einstein-Debye (SED) equation. Herein, the <sup>19</sup>F spin relaxation rates of difluprednate (DFPN) drug dissolved in polysorbate-80 (PS-80) micelles and castor oil swollen micelles (s-micelle) were measured and adequately fit using an isotropic diffusion model based spectral density function. Despite the high viscosity of PS-80 and castor oil, the fitting results revealed fast 4 and 12 ns dynamics of DFPN in both micelle globules. The observation of the fast ns motion in the viscous surfactant/oil micelle phase demonstrated motion decoupling between solute molecules inside micelles and the micelle itself in an aqueous solution. These observations support the role of intermolecular interaction in governing the rotational dynamics of small molecules, versus the viscosity of the solvent molecules as defined in the SED equation. Micelle ; Relaxation (psychology) ; Nuclear magnetic resonance ; Dynamics (music) ; Spin (aerodynamics) ; Spin echo ; Magnetic resonance imaging ; Materials science ; Physics ; Chemical physics ; Chemistry ; Physical chemistry ; Medicine ; Aqueous solution Surfactants and Colloidal Systems ; Analytical Chemistry and Chromatography ; Molecular spectroscopy and chirality
Authors: David Lansade | Jean‐François Roussel | Delphine Faye | Guillaume Rioland | Agnieszka Suliga | Orçun Ergincan
Source: IOP Conference Series Materials Science and Engineering (article, 2023-08-01)
Field: Chemistry — Organic Chemistry

Contamination Level Prediction: Progress in Species Separation by TGA/MS Abstract Molecular contamination can be detrimental to spacecraft life expectancy as it may induce changes to the properties of the surfaces on which it deposits. In order to control these potential issues, manufacturers need to assess in-flight contamination levels in the quite early design phases, possibly leading to design changes or extra material bake-out to fulfil requirements. The accuracy of model assessments may thus have direct impacts on missions and costs. Prediction of outgassing and deposition at mission timescale is done by extrapolating short-term on-ground experimental results, by fitting the latter with some empirical or physical laws. Common methods are the power law interpolation (in isothermal conditions) or the residence time approach (with thermally activated time constants), which leads to exponential decays in isothermal conditions. Although they allow fitting the measured outgassed flux over few-day-long experiments, their extrapolation to ten or fifteen-year-long missions is more challenging. Validating empirical laws might involve long-term empirical comparisons, while obviously the validation of physical models should start with checking their physics. In spite of many years trying, a basic difficulty was yet found to block significant progress on physical validation. As long as measurements are limited to the total mass on QCMs it looks possible to fit data as a sum of almost any law, such as residence time or diffusion models e.g. for outgassing. Following this observation, a conclusion was drawn that the only way to discriminate between two different physics was to characterize contamination at chemical species level. Such characterizations are a prerequisite to unravel the physics at play during several phenomena: outgassing, deposit films dynamics, photochemistry, environment/ATOX interactions, etc. This innovative approach, presented herein, aims at identifying outgassed contaminants by means of coupled thermogravimetric analysis and mass spectrometry. For this purpose, this paper reports the successful species separation and identification of contaminants outgassed from a material used in space applications: the epoxy adhesive Scotchweld EC-9323-2. Extrapolation ; Outgassing ; Interpolation (computer graphics) ; Physical law ; Contamination ; Environmental science ; Power law ; Diffusion ; Spacecraft ; Computer science ; Statistical physics ; Statistics ; Mathematics ; Physics ; Aerospace engineering ; Thermodynamics ; Engineering Chemical Thermodynamics and Molecular Structure ; Scientific Measurement and Uncertainty Evaluation ; Thermal and Kinetic Analysis
Authors: Hans-Peter Ebert | J. Manara | Gudrun Reichenauer
Source: International Journal of Thermophysics (article, 2023-06-12)
Field: Chemistry — Spectroscopy

Limits of Thermal Insulations: Heat Transfer within Evacuated Porous High-Performance Insulations Materials science ; Heat transfer ; Porosity ; Thermal ; Thermodynamics ; Composite material Aerogels and thermal insulation ; Radiative Heat Transfer Studies ; Heat and Mass Transfer in Porous Media
Authors: Manoj B. Mandake | Santosh Walke | Makarand Naniwadikar | Ganesh Patil | Sandhya Jadhav
Source: International Journal of Membrane Science and Technology (article, 2023-01-20)
Field: Chemistry — Analytical Chemistry

Experimental Investigations of the Removal of Methylene Blue from Waste Water using Agricultural Adsorbant Abstract: The colored organic or inorganic chemical compounds which can impart colour to other substance are the Dyes which did significant applications in the most industrial sectors like the textile industry, leather industry, paper industry, plastic, foodstuff industry etc, to impart color to their products. Due to the large volume of dye use in these businesses, a significant quantity of wastewater containing colored organics is generated. Because of insufficient dye-fiber fixation, during the dyeing process, half of the dye is lost in the wastewater. Peanut and rice husk are used to absorb MB from water. Initial Methylene Blue concentration, Peanut and Rice Husk dose, and pH were monitored and compared to current adsorbents to identify the optimal removal conditions. The equilibrium amount of MB adsorbed at time t (min) for rice husk and peanut hull are obtained as 5.1 and 5.19 mg/g respectively. As part of the research, an intra-particle diffusion model was implemented to regulate the mass transfer model's rate-controlling step mechanism. Husk ; Pulp and paper industry ; Dyeing ; Adsorption ; Wastewater ; Methylene blue ; Chemistry ; Waste management ; Agricultural waste ; Textile industry ; Organic chemistry ; Catalysis ; Engineering ; Botany Dye analysis and toxicity ; Water Quality Monitoring and Analysis
Authors: Ting Weng | Xiaolang Chen | Jun Qin | Qing Lv | Hongyu Shi | Lijin Zhang
Source: Journal of Molecular Liquids (article, 2023-07-28)
Field: Materials Science — Materials Chemistry

The effect of micro- and nano-γ-Al2O3 on the synthetic hydrotalcite and Congo red adsorption: Site energy distribution Adsorption ; Hydrotalcite ; Congo red ; Freundlich equation ; Diffusion ; Nano- ; Materials science ; Fourier transform infrared spectroscopy ; Chemical engineering ; Chemistry ; Organic chemistry ; Catalysis ; Thermodynamics ; Composite material Layered Double Hydroxides Synthesis and Applications ; Adsorption and biosorption for pollutant removal
Source: Biointerface Research in Applied Chemistry (article, 2023-12-15)
Field: Materials Science — Materials Chemistry

Removal of Gallic Acid Over Layered Double Hydroxide: Material Design and Kinetic Studies The present study focused on removing gallic acid on the layered double hydroxide (Mg-Al-LDH) material synthesized by the co-precipitation method with a molar ratio of Mg/Al = 2. The elaborated Mg-Al-LDH was characterized using chemical analysis, XRD, FTIR, SEM, and specific surface area techniques. Langmuir and Freundlich isotherms and kinetic studies were also investigated. The adsorption tests demonstrated that the GA adsorption onto the Mg-Al-LDH is dependent on the material dose, GA concentration, and the pH of the solution. It was observed that the yield of the dye removal passed from 27.37 to 99.9 %; when the Mg-Al-HDL dose increased from 0.05 to 0.8 g/L. The results obtained showed that the adsorption of GA on Mg-Al-LDH is an endothermic reaction, spontaneous, follows second-order kinetics, and the Langmuir isotherm observed a better description. Kinetic energy ; Gallic acid ; Hydroxide ; Layered double hydroxides ; Chemical engineering ; Materials science ; Chemistry ; Inorganic chemistry ; Organic chemistry ; Engineering ; Physics Layered Double Hydroxides Synthesis and Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Chemical Synthesis and Reactions
Authors: Mutaz Salih | Babiker Y. Abdulkhair | Mansour Alotaibi
Source: Chemistry (article, 2023-08-24)
Field: Materials Science — Materials Chemistry

Insight into the Adsorption Behavior of Carbon Nanoparticles Derived from Coffee Skin Waste for Remediating Water Contaminated with Pharmaceutical Ingredients Coffee skins, a cheap, agricultural waste, were carbonized in a tubular furnace under a nitrogen stream and then ball milled to fabricate coffee skin-carbon-nanoparticles (CCNPs). SEM showed 35.6–41.6 nm particle size. The 26.64 and 43.16 peaks in the XRD indicated a cubic graphite lattice. The FT-IR broadband revealed a 2500–3500 cm−1 peak, suggesting an acidic O-H group. CCNPs possessed a type-H3-loop in the N2-adsorption-desorption analysis, with a surface of 105.638 m2 g−1. Thereafter, CCNPs were tested for ciprofloxacin (CPXN) adsorption, which reached equilibrium in 90 min. CCNPs captured 142.6 mg g−1 from 100 mg L−1 CPXN, and the 5:12 sorbent mass-to-solution volume ratio was suitable for treating up to 75 mg L−1 contamination. The qt dropped from 142.6 to 114.3 and 79.2 mg g−1 as the temperature rose from 20 °C to 35 °C and 50 °C, respectively, indicating exothermic adsorption. CPXN removal efficiency decreased below pH 5.0 and above pH 8.0. Kinetically, CPXN adsorption fits the second-order model and is controlled by the liquid-film mechanism, indicating its preference for the CCNPs’ surface. The adsorption agreement with the liquid-film and Freundlich models implied the ease of CPXN penetration into the CCNP inner shells and the multilayered accumulation of CPXN on the CCNPs’ surface. The negative ∆H° and ∆G° revealed the exothermic nature and spontaneity of CPXN adsorption onto the CCNP. The CCNPs showed an efficiency of 95.8% during four consecutive regeneration-reuse cycles with a relative standard deviation (RSD) of 3.1%, and the lowest efficiency in the fourth cycle was 92.8%. Adsorption ; Carbonization ; Desorption ; Carbon black ; Endothermic process ; Chemistry ; Graphite ; Materials science ; Nanoparticle ; Nuclear chemistry ; Chemical engineering ; Analytical Chemistry (journal) ; Chromatography ; Organic chemistry ; Nanotechnology Carbon and Quantum Dots Applications ; Adsorption and biosorption for pollutant removal ; Graphene and Nanomaterials Applications
Authors: Yong Guo | Jindian Cai | Yaodong Liang | Yongjun He
Source: Water Science & Technology (article, 2023-11-21)
Field: Materials Science — Materials Chemistry

Preparation of emulsion hydrogels encapsulating extractant by the Pickering emulsion template method to recover lanthanum ions in aqueous solutions To solve the problem of liquid-liquid extraction of La(III), the oil-in-water Pickering emulsions were prepared by utilizing the aqueous solution of sodium alginate as the continuous phase, kerosene-diluted extractant di-(2-ethylhexyl) phosphate (P204) as the dispersed phase, and modified silica as an emulsifier. Then the emulsions were added to a calcium chloride solution to prepare the Pickering emulsion hydrogels (PEHGs) to better remove La(III). The PEHGs were characterized using Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. The adsorption properties of PEHGs for La(III) in the aqueous solution were investigated using a UV-vis spectrophotometer. The study found that P204 was successfully coated by hydrogels and reached the highest adsorption capacity of 48 mg/g at pH 4. The amount of adsorption increased with the rise in temperature from 298 to 318 K. La(III) adsorption experimental data were more consistent with the pseudo-second-order kinetic model and the Langmuir isotherm model. Thermodynamic parameters showed that the adsorption of La(III) by PEHGs was a spontaneous endothermic process. The internal diffusion model revealed a linear relationship, indicating that internal diffusion played a role in the adsorption process. The encapsulating property of PEHGs indicated its potential usefulness in industrial wastewater for treating La(III). Aqueous solution ; Adsorption ; Pickering emulsion ; Chemistry ; Thermogravimetric analysis ; Emulsion ; Chemical engineering ; Fourier transform infrared spectroscopy ; Lanthanum ; Langmuir adsorption model ; Self-healing hydrogels ; Endothermic process ; Nuclear chemistry ; Aqueous two-phase system ; Inorganic chemistry ; Polymer chemistry ; Organic chemistry Pickering emulsions and particle stabilization ; Extraction and Separation Processes ; Radioactive element chemistry and processing
Authors: Jie Zhang | Xuemei Zhang | Xin Li | Weiyan Li | Shanshan Mao | Shiyi He | Xiao Wu | Cuiqing Tang | Jiao Yu | Liqin Pan | Xing Zhou
Source: Environmental Progress & Sustainable Energy (article, 2023-12-11)
Field: Chemistry — Analytical Chemistry

High efficiency removal of ibuprofen in water using activated carbon derived from <i>Radix Angelica Dahurica</i> residue Abstract The exploitation and utilization of Traditional Chinese medicine have annually produced 30 million tons of waste residues including Radix Angelica Dahurica residue (RAR), which raised environmental concerns. Meantime, the non‐steroidal anti‐inflammatory drug of ibuprofen (IBP) is an emerging contaminant in the aquatic environment, annually producing up to 9000 tons in China. After extracting the active substance, RAR is prepared as activated carbon (AC) for the purification of IBP wastewater. Two kinds AC modified without (RAR‐AC) and with phosphoric acid (M‐RAR‐AC) were characterized by FT‐IR, TG, BET and SEM. The phosphoric acid activation contributed to the high BET surface area (564.9914 m 2 g −1 ) and large total pore volume (0.4894 cm 3 g −1 ). M‐RAR‐AC showed 7.7 folds (15 min) and 2.7 folds (30 min) higher extent of IBP removal compared to commercial activated carbon (C‐AC). The enhancement of IBP removal with M‐RAR‐AC was investigated further by varying initial pollutant concentration, absorbent dosage, temperature, pH and rotating speed. Especially, temperature nearly has no effect on IBP removal by M‐RAR‐AC. Isotherm and kinetic studies suggested IBP was adsorbed on the heterogeneous surface in multilayer form and chemisorption played the dominant role in IBP removal. IBP removal of 93.3 ± 0.1% and 64.2 ± 2.8% was achieved for first and fifth cycle, respectively. The IBP removal on M‐RAR‐AC may be accomplished by a variety of interactions such as electrostatic attraction, pore‐filling, hydrogen bonding, and π‐π interaction. These findings provide new insights into the utilization of RAR for preparing AC and highlight the potential applications for treating industrial wastewater. Phosphoric acid ; Activated carbon ; Chemistry ; Adsorption ; BET theory ; Nuclear chemistry ; Wastewater ; Specific surface area ; Chemisorption ; Pollutant ; Organic chemistry ; Environmental engineering ; Catalysis ; Environmental science Analytical chemistry methods development ; Pharmaceutical and Antibiotic Environmental Impacts ; Adsorption and biosorption for pollutant removal
Authors: Vladislav V. Shunaev | Nadezhda Bobenko | П. М. Корусенко | Valeriy Egorushkin | Olga E. Glukhova
Source: International Journal of Molecular Sciences (article, 2023-01-09)
Field: Materials Science — Materials Chemistry

Carboxyl Functionalization of N-MWCNTs with Stone–Wales Defects and Possibility of HIF-1α Wave-Diffusive Delivery Nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) are widely used for drug delivery. One of the main challenges is to clarify their interaction with hypoxia-inducible factor 1 alpha (HIF-1α), the lack of which leads to oncological and cardiovascular diseases. In the presented study, N-MWCNTs were synthesized by catalytic chemical vapor deposition and irradiated with argon ions. Their chemical state, local structure, interfaces, Stone-Wales defects, and doping with nitrogen were analyzed by high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Using experimental data, supercells of functionalized N-MWCNTs with an oxygen content of 2.7, 4 and 6 at. % in carboxyl groups were built by quantum chemical methods. Our analysis by the self-consistent charge density functional tight-binding (SCC DFTB) method shows that a key role in the functionalization of CNTs with carboxyl groups belongs to Stone-Wales defects. The results of research in the decoration of CNTs with HIF-1α demonstrate the possibility of wave-diffusion drug delivery. The nature of hybridization and relaxation determines the mechanism of oxygen regulation with HIF-1α molecules, namely, by OH-(OH-C) and OH-(O=C) chemical bonds. The concentration dependence of drug release in the diffusion mode suggests that the best pattern for drug delivery is provided by the tube with a carboxylic oxygen content of 6 at. %. X-ray photoelectron spectroscopy ; Surface modification ; Carbon nanotube ; Chemical state ; High-resolution transmission electron microscopy ; XANES ; Raman spectroscopy ; Chemical vapor deposition ; Materials science ; Nanotechnology ; Molecule ; Chemical engineering ; Transmission electron microscopy ; Chemistry ; Spectroscopy ; Organic chemistry ; Physical chemistry Carbon Nanotubes in Composites ; Nanopore and Nanochannel Transport Studies ; Photoreceptor and optogenetics research
Authors: Marco Zannotti | Andrea Rossi | Marco Minicucci | Stefano Ferraro | Laura Petetta | Rita Giovannetti
Source: International Journal of Molecular Sciences (article, 2023-04-18)
Field: Materials Science — Materials Chemistry

Water Decontamination from Cr(VI) by Transparent Silica Xerogel Monolith Cr(VI) is highly soluble and mobile in water solution and extremely toxic. In order to obtain a specific material with adsorption properties towards Cr(VI), and that can be used in environmental remediation of water contaminated with Cr(VI), one-step sol-gel technique, at low temperature (50 °C), has been optimized to prepare transparent silica-based xerogel monolith by using tetraethyl orthosilicate as precursor. The obtained xerogel, with disk shape, was fully characterized by Raman, BET, FE-SEM and XRD analysis. The results indicated that the material showed silica amorphous phase and high porosity. The study of the adsorption properties towards different concentrations of Cr(VI), in the form of HCrO<sub>4</sub><sup>-</sup> in acidic condition, showed prominent results. The absorption kinetics were evaluated by studying different models, the final result showing that the absorption of Cr(VI) occurred through intra-particle diffusion process, following two steps, and that the absorption equilibrium is regulated by Freundlich isotherm model. The material can be restored by reducing the hazardous Cr(VI) to Cr(III), a less toxic form of chromium, by 1,5-diphenylcarbazide, and with successive treatment in acidic water. Monolith ; Human decontamination ; Chemistry ; Chemical engineering ; Chromatography ; Waste management ; Catalysis ; Organic chemistry Mesoporous Materials and Catalysis ; Aerogels and thermal insulation ; Catalytic Processes in Materials Science