jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: D. A. Sveshnikova | D.I. Rabadanova | David R. Ataev | А. Ш. Рамазанов
Source: Сорбционные и хроматографические процессы (article, 2024-02-12)
Field: Chemistry — Spectroscopy

Physico-chemical and sorption properties of original and modified clay from the Levashinskoye deposit of the Republic of Dagestan The high sorption, ion exchange, and catalytic properties of natural clay minerals determine their widespread use in various technological processes. More than 30 deposits of various clays have been identified and explored within the territory of the Republic of Dagestan, one of which is the Levashinskoye deposit. Available data on the adsorption of ions of rare alkali (Rb+ and Cs+) and alkaline earth (Sr2+) metals on clay minerals make the task of study of the possibility of using clay from this deposit as a sorbent for extracting these ions from aqueous solutions even more relevant. This, in turn, is due to the need for effective sorbents for concentrating and extracting ions of alkali and alkaline earth metals when solving problems of complex processing of hydromineral raw materials. The purpose of this study was the investigation of the physicochemical and sorption properties of Rb+, Cs+, Sr2+ native and hydrochloric acid-modified clay from the Levashinskoye deposit of the Republic of Dagestan. Based on a comprehensive study, the mineralogical composition of native clay was established, the main clay minerals of which were: illite, nontronite, and montmorillonite. In addition, the sample contained calcite and quartz. In order to increase the content of clay minerals, with which the sorption activity of clay is mainly associated, the original clay was treated with a 1 M hydrochloric acid solution, which led to an increase in the content of clay minerals from 62% in the original clay to 75% in the clay treated with HCl. Sorption experiments for Rb+, Cs+, Sr2+ were carried out in model solutions, the concentration of the studied ions in solutions varied in the range of 20-700 mg/dm3. It was shown that the equilibrium of adsorption of these ions on the studied clay can be satisfactorily described both by equations for a non-uniform surface (Freundlich, Temkin, Dubinin-Radushkevich) and by the Langmuir isotherm for a homogeneous surface. It was found that the modification of the original clay with a solution of hydrochloric acid increases the sorption capacity of the clay for the studied ions. It has been established that the main mechanism of sorption of these ions on both the original and modified clay of the Levashinskoye deposit was ion exchange, while other mechanisms cannot be excluded. The study of the kinetics of Rb+, Cs+, Sr2+ sorption on modified clay showed that the sorption process of these ions can be described by a mixed-diffusion model and a pseudo-second-order model. Sorption ; Clay minerals ; Chemical engineering ; Chemistry ; Geochemistry ; Mineralogy ; Environmental chemistry ; Geology ; Adsorption ; Engineering ; Physical chemistry Adsorption, diffusion, and thermodynamic properties of materials ; Advanced Theoretical and Applied Studies in Material Sciences and Geometry
Authors: Maham Tanveer | Zhou Yang | Simon Niklaus | Ali Mahdavi Amiri | Hao Zhang | K.K. Singh | Nanxuan Zhao
Source: arXiv (Cornell University) (preprint, 2024-12-17)
Field: Materials Science — Polymers and Plastics

MotionBridge: Dynamic Video Inbetweening with Flexible Controls By generating plausible and smooth transitions between two image frames, video inbetweening is an essential tool for video editing and long video synthesis. Traditional works lack the capability to generate complex large motions. While recent video generation techniques are powerful in creating high-quality results, they often lack fine control over the details of intermediate frames, which can lead to results that do not align with the creative mind. We introduce MotionBridge, a unified video inbetweening framework that allows flexible controls, including trajectory strokes, keyframes, masks, guide pixels, and text. However, learning such multi-modal controls in a unified framework is a challenging task. We thus design two generators to extract the control signal faithfully and encode feature through dual-branch embedders to resolve ambiguities. We further introduce a curriculum training strategy to smoothly learn various controls. Extensive qualitative and quantitative experiments have demonstrated that such multi-modal controls enable a more dynamic, customizable, and contextually accurate visual narrative. Computer science Textile materials and evaluations ; Advanced Sensor and Energy Harvesting Materials ; Tactile and Sensory Interactions
Authors: Shahnaz Sargazi | Mohammad Taghi Ghaneian | Mashaallah Rahmani | Ali Asghar Ebrahimi
Source: Heliyon (article, 2024-10-30)
Field: Chemistry — Analytical Chemistry

Application of cloud point extraction coupled with derivative spectrophotometry to remove binary mixture of Cresol Red and Methyl Orange dyes from aqueous solutions: Box–behnken design optimization Cloud point extraction (CPE) was employed to eliminate Cresol Red (CR) and Methyl Orange (MO), as anionic dyes in a binary mixture from aqueous solutions. To remove these dyes Triton X-100 and NaCl at pH 5.7 were utilized. In this vein, wavelengths of 365 nm and 520 nm were respectively selected for CR and MO using the derivative spectrophotometer and first-order derivatives. According to based on the first-order derivative spectrophotometry, the recoveries rised from 94.3 to 99.5 % for CR and from 94.6 to 99.1 % for MO. In the following, the response surface methodology was administered to investigate the effect of surfactant concentration, temperature, and time on the dyes' elimination process. The quadratic mathematical model was obtained from the Box-Behnken design (BBD) matrix and developed to estimate the impact of each variable and its relationship with the elimination parameters. Later, coefficients of determination (R<sup>2</sup>) ≥0.97 were obtained using model equations and comparison between predicted and empirical values. Analysis of variance estimated the models' significance and anticipation while processing the study variables. Based on the results, the model of pseudo-first-order in kinetic modelling can best describe dyes adsorption among the studied models. The analyzed dyes adhere to the Langmuir model with correlation values of 0.86 for CR and 0.87 for MO. The monolayer capacity (Q<sub>max</sub>) was determined as 0.77 mol/mol for CR and 26.41 mol/mol for MO. Box–Behnken design ; Cloud point ; Spectrophotometry ; Aqueous solution ; Chromatography ; Methyl orange ; Chemistry ; Extraction (chemistry) ; Orange (colour) ; Response surface methodology ; Organic chemistry ; Photocatalysis ; Food science Dye analysis and toxicity ; Analytical chemistry methods development ; Toxic Organic Pollutants Impact
Authors: Tarek M. Madkour | Rasha E. Elsayed | Rasha A. Azzam
Source: Gels (article, 2024-11-22)
Field: Chemistry — Organic Chemistry

Environmentally Friendly Nanoporous Polymeric Gels for Sustainable Wastewater Treatment Environmentally friendly nanoporous gels are tailor-designed and employed in the adsorption of toxic organic pollutants in wastewater. To ensure the maximum adsorption of the contaminant molecules by the gels, molecular modeling techniques were used to evaluate the binding affinity between the toxic organic contaminants such as methylene blue (MB) and Congo red (CR) and various biopolymers. To generate nanopores in the matrix of the polymeric gels, salt crystals were used as porogen. The pores were then used to accommodate catalytic nickel (Ni<sup>0</sup>) nanoparticles. Under UV irradiation, the nanoparticles demonstrated the effective adsorption and photocatalytic degradation of both the methylene blue and Congo red dyes, achieving removal efficiencies of up to 90% for MB and 80% for CR. The thermodynamic analysis suggested a spontaneous endothermic dissociative adsorption mechanism, which implies the oxidative catalytic degradation of the dyes. The kinetic modeling suggested a pseudo-second-order model, while the model for intra-particle diffusion revealed that Congo red diffuses faster than methylene blue. MB adsorption followed a Langmuir isotherm, while CR adsorption followed a linear isotherm. The results confirm that dye molecules initially undergo physisorption and subsequent dissociative adsorption. The products of the catalytic degradation of methylene blue continue to be absorbed on the surface of the nanoparticles, while those of Congo red switch to preferential desorption. Environmentally friendly ; Nanoporous ; Wastewater ; Materials science ; Waste management ; Nanotechnology ; Chemical engineering ; Environmental science ; Environmental engineering ; Engineering Nanomaterials for catalytic reactions ; Adsorption and biosorption for pollutant removal ; Advanced Photocatalysis Techniques
Authors: Noor Dia Jaffer | Safa Majeed Hameed | Athir Haddad
Source: METHODS AND OBJECTS OF CHEMICAL ANALYSIS (article, 2024-01-01)
Field: Chemistry — Analytical Chemistry

New Semi-IPN hydrogels for Removal of High Concentrated Congo Red Dye from Aqueous Solutions This study presents a simple, rapid, and accurate spectrophotometric method for the determination of Aripiprazole (ARP) in tablets. The determination procedure is based on the reaction of ARP with 7,7,8,8-tet racyanoquinodimethane (TCNQ), producing a colored product that was quantitated spectrophotometrically at 392 nm. Various variables affecting the reaction were optimized. The method exhibited a good linearity range with a correlation coefficient of 0.9994, observed as 0.25–3 μg/mL. The developed method was validated according to the International Council for Harmonisation (ICH) guidelines, assessing specificity, linearity, accuracy, precision, robustness, limit of detection (LOD), and limit of quantitation (LOQ). The formation of the CT-complex and the interaction sites were confirmed by elemental analysis, DSC, IR, and 1H NMR spectroscopy. The method was successfully applied to the determination of ARP in pharmaceutical preparation. Congo red ; Self-healing hydrogels ; Aqueous solution ; Chemical engineering ; Chemistry ; Polymer chemistry ; Materials science ; Organic chemistry ; Adsorption ; Engineering Dye analysis and toxicity ; Nanomaterials for catalytic reactions ; Adsorption and biosorption for pollutant removal
Authors: Zhaojin Yu | Haiyang Wang | Zhuo Li | Dingwei Yan | Ke Liang | Xiaopeng Yang | Jianhua Qiu | Fu Du | Xiaoming Ji
Source: Flavour and Fragrance Journal (article, 2024-12-17)
Field: Materials Science — Materials Chemistry

Thermal Decomposition Kinetics Analysis and Its Application to Cigarette Flavouring of Methyl Cyclopentenolone Succinate Menthol Diester ABSTRACT Methyl cyclopentenolone succinate menthol diester (compound 5) was synthesised from methyl cyclopentenolone, menthol and succinic anhydride using dicyclohexylcarbodiimide (DCC) and 4‐dimethylaminopyridine (DMAP) methods. The thermal decomposition process and kinetic behaviour of the compounds were studied at various heating rates (10°C, 20°C, 40°C, 60°C and 80°C min −1 ) using thermogravimetry‐derivative thermogravimetry (TG‐DTG), Kissinger‐Akahira‐Sunose (KAS) method, Flynn‐Wall‐Ozawa (FWO) method and Coats–Redfern method. The research revealed that TG curves approached the high‐temperature end with increasing heating rates, and the peak temperature of heat loss rate on the DTG curves tended to rise, but the magnitude of the change was smaller than that of heating rate. The apparent activation energy ( E a ) of thermal decomposition increased with the conversion rate. The E a of compound 5 ranged from 77.65 to 154.05 kJ mol −1 and from 82.56 to 156.43 kJ mol −1 calculated by KAS and FWO, respectively. The thermal decomposition process models of the compounds were found to be one‐dimensional diffusion models (D1). The results of the kinetic compensation effect showed that the fitting result of the KAS method was better than that of the FWO method. Pyrolysis results indicated the production of aromatic substances such as methyl cyclopentenolone, menthol and esters. Additionally, the results of cigarette flavouring showed that the smoking quality of cigarettes was improved by adding compound 5. In summary, the findings of this study not only offer insights into the thermal decomposition and development of slow‐release flavours under heated conditions, but also provide valuable references for assessing the thermal stability and utilisation potential of various substances, including biomass. Chemistry ; Thermogravimetry ; Thermal decomposition ; Decomposition ; Activation energy ; Pyrolysis ; Menthol ; Kinetics ; Organic chemistry ; Thermal analysis ; Nuclear chemistry ; Thermal ; Inorganic chemistry ; Thermodynamics Thermal and Kinetic Analysis ; Thermochemical Biomass Conversion Processes ; Free Radicals and Antioxidants
Authors: Lars Grunenberg | Christopher Keßler | Tiong Wei Teh | Robin Schuldt | Fabian Heck | Johannes Kästner | Joachim Groß | Niels Hansen | Bettina V. Lotsch
Source: ChemRxiv (preprint, 2024-04-09)
Field: Chemistry — Electrochemistry

Self-Diffusion of Acetonitrile in a Covalent Organic Framework: Simulation and Experiment Covalent Organic Frameworks have emerged as a new class of porous materials whose sorption properties have so far been studied primarily with physisorption techniques. Quantifying the self-diffusion of guest molecules in the interior of their nanometer-sized pores allows for a better understanding of confinement effects or transport limitations and is thus vital for various applications ranging from molecular separation to catalysis. Using a combination of pulsed field gradient nuclear magnetic resonance (PFG NMR) measurements and molecular dynamics (MD) simulations we have probed the self-diffusion of acetonitrile in the 1.7 nm diameter pore channels of two imine-linked COFs (PI-3-COF) featuring different levels of crystallinity and porosity, between 270 K and 300 K. In the sample showing higher crystallinity and porosity, we observe clear evidence for anisotropic diffusion parallel to the pore channel direction as characterized by a diffusion coefficient of D_par = 6.1 × 10^-10 m2/s at T = 300 K, consistent with 1D transport. Self-diffusion in the pores vs. bulk liquid is thus reduced by a factor of 7.4, in good agreement with MD simulations which predict a reduction of the self-diffusion coefficient by a factor of 5.4 compared to the bulk liquid value, assuming an offset-stacked COF layer arrangement. In contrast, more frequent diffusion barriers give rise to isotropic, yet significantly reduced diffusivities in the low-porosity sample (D_B = 1.4 × 10^-11 m2/s at T = 300 K). Our multimodal study thus highlights the significant influence of real structure effects such as stacking faults and grain boundaries on the long-range diffusivity of molecular guest species, while suggesting efficient intracrystalline transport at short diffusion times. Acetonitrile ; Diffusion ; Covalent bond ; Chemistry ; Chemical physics ; Computer science ; Organic chemistry ; Physics ; Thermodynamics Electrochemical Analysis and Applications ; Ionic liquids properties and applications ; Microfluidic and Capillary Electrophoresis Applications
Authors: Harrison Landfield | Nicholas Kalamaris | Muzhou Wang
Source: ChemRxiv (preprint, 2024-02-12)
Field: Chemistry — Physical and Theoretical Chemistry

Extreme Dependence of Dynamics on Concentration in Highly Crowded Polyelectrolyte Solutions Charge carrying species, such as polyelectrolytes, are vital to natural and synthetic processes that rely on their dynamic behavior. Here, we utilize single molecule methods to probe this dynamic behavior using polylysine as a model polyelectrolyte. Through single-particle tracking techniques, the diffusivity of individual polyelectrolyte chains and overall system viscosity are determined for concentrated polylysine solutions. These studies show experimental scaling dependences much stronger than theoretical predictions for both neutral polymers and polyelectrolytes and draw into question whether power law based scaling theories are appropriate to describe concentrated charged systems. Similar dependences are observed in concentrated solutions prepared at a variety of pH and counterion conditions. Hindered system dynamics are attributed to contributions from monomeric friction and the large effective excluded volume of polyelectrolyte chains leading to glassy dynamics. These forces restrict the movement of polymers through the sample and their effects are seen over a wide range of concentrations. The framework of the Vrentas Duda free volume theory is used to compare polyelectrolyte and neutral systems. Supported by this theory, when the mass associated with the counterions is excluded from the total polymer mass diffusive scaling across environmental conditions collapses onto a common trendline. Overall, these results are applicable to behavior in crowded biological systems, such as intracellular environments where the mobility of proteins is strongly inhibited. Polyelectrolyte ; Dynamics (music) ; Statistical physics ; Chemical physics ; Chemistry ; Physics ; Polymer ; Organic chemistry Electrostatics and Colloid Interactions ; Surfactants and Colloidal Systems ; Microfluidic and Capillary Electrophoresis Applications
Authors: Thomas L. Goût | Anamul H. Mir | Simon M. Fairclough | D. Pletser | Ian Farnan
Source: npj Materials Degradation (article, 2024-05-25)
Field: Materials Science — Materials Chemistry

Undetected perovskite phase interference with zirconolite dissolution measurements Abstract Zirconolite ceramics present a chemically durable host matrix for waste actinides, but zirconolite dissolution rates reported in the literature often vary significantly. Here, the release of Ca and Al from a hot isostatically pressed zirconolite (Ca 0.8 Zr 0.9 Ce 0.3 Ti 1.6 Al 0.4 O 7.0 ) was shown to be predominantly driven by preferential dissolution of minor perovskite and alumina phases. Both phases were undetectable by XRD, and the perovskite was difficult to detect by SEM-EDS. Whilst the zirconolite phase exhibited no signs of alteration, dissolution of the perovskite proceeded congruently without forming a hydrated altered layer or diffusion of protons into the solid that would be indicative of an ion-exchange mechanism. The weak temperature dependence of dissolution (40, 90 and 150 °C) showed that kinetics were limited by transport and a mixed transport-surface controlled reaction for Ca and Al, respectively. A significant H 2 O-D 2 O isotope effect on dissolution was observed for Ca but not for Al at all temperatures. The former was consistent with an abated rate of hydrolysis in the absence of a contribution from diffusion, whilst the latter could be attributed to differences in the activated complex for Ca and Al release through hydrolysis. These results demonstrate the role of a secondary phase perovskite in the dissolution kinetics of zirconolite even when perovskite occurs at low concentration and evades detection by bulk techniques such as XRD. This study provides a potential explanation of variations in zirconolite ceramic dissolution rates present in the literature and provides a null result to tests of an incongruent Ca release mechanism from zirconolite. Zirconolite ; Dissolution ; Perovskite (structure) ; Phase (matter) ; Materials science ; Interference (communication) ; Chemical engineering ; Chemistry ; Crystallography ; Engineering ; Telecommunications Nuclear materials and radiation effects ; Electronic and Structural Properties of Oxides ; Luminescence Properties of Advanced Materials
Authors: Yatong Zhao | Ping Chen | Xiang Wang | Hanna Hlushko | Jay A. LaVerne | Lili Liu | Carolyn I. Pearce | Zhe-Ming Wang | Kevin M. Rosso | Xin Zhang
Source: Environmental Science & Technology (article, 2024-11-26)
Field: Chemistry — Inorganic Chemistry

Effect of <sup>60</sup>Co Irradiation on Boehmite Dissolution in Caustic Solutions Here, we examine how radiation impacts the dissolution behavior of boehmite by subjecting dry nanoparticles of different sizes to <sup>60</sup>Co γ radiation and subsequently analyzing their dissolution behavior in caustic solutions as a function of temperature. The measured kinetics show that irradiation with an amount 228.24 Mrad significantly slows the dissolution rate, particularly for smaller sizes at lower temperatures. Specifically, the temperature-dependent dissolution rates of irradiated 20 nm boehmite versus pristine material in 3 M NaOH solutions were several times lower (e.g., rate constant of 0.026 vs 0.075 h<sup>-1</sup> at 60 °C), with an apparent activation energy 40 kJ mol<sup>-1</sup> higher. Although various imaging techniques and X-ray diffraction measurements consistently revealed no obvious differences between pristine and irradiated samples, after irradiation significant binding energy shifts were detected in the X-ray photoelectron Spectroscopy peaks of Al 2p and O 1s, and a change in their relative intensities indicated a lower O/Al ratio. This suggests that γ-irradiation may stabilize boehmite particle surfaces by driving their chemistry and structure toward more stable aluminum oxide forms. This finding may help explain slower dissolution rates of boehmite in nuclear waste and may be useful for the development of more robust predictive models and effective strategies for waste processing. Boehmite ; Dissolution ; Irradiation ; Caustic (mathematics) ; Nanoparticle ; Chemistry ; Radiochemistry ; Mineralogy ; Materials science ; Nuclear chemistry ; Nanotechnology ; Physics ; Physical chemistry ; Nuclear physics ; Organic chemistry Radioactive element chemistry and processing ; Nuclear materials and radiation effects ; Chemical Synthesis and Characterization
Authors: Abdelali Gherbia | Djamel Sahel | Abdallah Bouabidi | Abdelmalek Chergui
Source: International Journal of Energy Research (article, 2024-01-01)
Field: Chemistry — Analytical Chemistry

A Kinetic and Thermodynamic Study of Cationic Thiazine Dye Removal From Aqueous Solution by Date Stones Variety Ghars Date stones represent an unused resource that is often incinerated or disposed of directly as waste. Therefore, great attention has been paid to transforming it into useful products. This study was conducted to evaluate the ability of activated carbon prepared from the stones of one of the date varieties, called “Ghars,” as an agricultural waste to remove a basic dye, methylene blue (MB), from aqueous solutions. The surface characteristics of prepared activated carbon Ghars stones (ACGS) were characterized using scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Physical and chemical factors affecting MB adsorption, such as contact time, the mass of adsorbent, potential of hydrogen (pH) value, and initial concentration of the solution, were studied in a batch system. Isotherm equilibrium data are well described by the Freundlich model ( R 2 = 0.98), and the experimental adsorption capacity was found to be ( q e .exp = 130.3 mg/g) at 298 K. The kinetic study indicates that the adsorption process of MB follows the pseudo‐second‐order (PSO) model. ΔH ° (19.94 J/mol) and Δ G ° (−1.101, −1.127, −1.430, and −1.546 kJ/mol) values revealed that the adsorption of MB on ACGS was endothermic nature, feasible, and spontaneous. The positive value of ∆ S° (15.67 kJ/mol) confirmed the increased in the randomness at the solid‐solution interface during the adsorption process of MB on ACGS. MB adsorption/desorption experiments demonstrated the reusability of ACGS for five consecutive cycles. The results showed that ACGS developed from agricultural waste could be successfully used to remove cationic organic pollutants from wastewater. Thiazine ; Aqueous solution ; Cationic polymerization ; Kinetic energy ; Chemistry ; Chemical engineering ; Thermodynamics ; Physical chemistry ; Organic chemistry ; Engineering ; Physics Dye analysis and toxicity