Article
Chemistry, Physical
Pooja Sahu, Ashish KumarSingha Deb, Sk Musharaf Ali, K. T. Shenoy
Summary: Molecular dynamics simulations were used to gain insights into the uranium extraction process in biphasic systems. The results showed that the extraction of uranyl ions to the organic phase increased with concentration, and the complexation of UO2+2-TBP happened at the interface, not in the organic phase. Further studies are needed to resolve the complex issue of uranyl ion complexation at the interface.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Multidisciplinary
Liyang Zhu, Youshi Lan, Qian Liu, Xuan Hao, Jin Zhou, Suliang Yang
Summary: The study investigates the complexation of solid uranyl nitrate with TBP in supercritical CO2, revealing the formation of poly-core uranyl-TBP species in the anhydrous system but the prevention of poly-core species in the hydrated system. Complexation development is influenced by the TBP to uranyl nitrate ratio, solute densities, and water participation, with kinetically favoring species gradually converting into thermodynamically stable species by ligand exchange.
Article
Chemistry, Multidisciplinary
Tarun Maity, Abhishek Aggarwal, Subhadeep Dasgupta, Vasumathi Velachi, Ashish Kumar Singha Deb, Sk Musharaf Ali, Prabal K. Maiti
Summary: Using MD simulations and experimental studies, we investigated the adsorption and removal of uranyl ions from aqueous solutions using PAMAM dendrimers. Our results show that PAMAM has a high adsorption capacity for uranyl ions, which increases with higher ion concentrations and dendrimer generations. This suggests that PAMAM is an effective adsorbent for removing uranyl ions.
Article
Chemistry, Inorganic & Nuclear
Qi Yang, Tingting Liu, Jiwen Tan, Liyang Zhu, Qian Liu, Suliang Yang, Guoxin Tian
Summary: The complexation of uranium(VI) with dipicolinic acid and the presence of a protonated complex in aqueous solutions were investigated in this study. The stability constants of known complexes were reevaluated considering the missing protonated species. While a crystal of a solid compound with a specific coordination mode was successfully grown, the corresponding complex species in solution could not be clearly identified.
INORGANIC CHEMISTRY
(2022)
Article
Energy & Fuels
Yunfei Xu, Zhihua Wang, Xue Han, Jiajun Hong, Yong Wang
Summary: This paper investigates the impact of sodium dodecyl benzene sulfonate (SDBS) concentration on the stability of crude oil-mineral water interfacial film. By constructing different simulation systems and comparing with experimental results, it is found that the number of SDBS molecules per unit area of the film increases with concentration, leading to increased film thickness and interface formation energy. In addition, inorganic ions weaken the performance of SDBS and detrimentally affect the structural strength and stability of interfacial films.
Article
Chemistry, Multidisciplinary
Lijuan Feng, Hui Wang, Tiantian Feng, Bingjie Yan, Qiuhan Yu, Jiacheng Zhang, Zhanhu Guo, Yihui Yuan, Chunxin Ma, Tao Liu, Ning Wang
Summary: An adaptive coordination structure is crucial for selectively extracting uranium from seawater. By using molecular imprinting, a multivariate metal-organic framework (MOF) adsorbent has been synthesized, which shows high selectivity for uranium and vanadium.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Junyi Li, Zoltan Szabo, Mats Jonsson
Summary: This study identified the ternary uranyl-peroxo-chloro and uranyl-peroxo-bromo complexes using spectroscopy techniques. The uranyl-peroxo-chloro complex was found to be more stable than the uranyl-peroxo-bromo complex, which transforms into studtite at high uranyl and H2O2 concentrations. Studtite was also found to dissolve under high ionic strength conditions, suggesting it may not be a stable solid phase under very saline conditions. The uranyl-peroxo-bromo complex was shown to facilitate H2O2 decomposition via reactive intermediates.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Hanna Oher, Geoffroy Ferru, Laurent Couston, Laurence Berthon, Dominique Guillaumont, Florent Real, Thomas Vercouter, Valerie Vallet
Summary: Uranyl binitrate complexes are of particular interest in the nuclear industry, with the modified PUREX extraction process designed to extract U(VI) in a specific form. The DEHiBA ligands can coordinate uranyl in either trans- or cis-position with respect to the nitrate ligands, and these conformers may coexist in solution. The study aims to determine if these conformers can be discriminated by their spectroscopic properties through modeling and experimental verification.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Chunlu Li, Ao Li, Xingchang Cha, Qingxiang Liu, Jun Gao, Dongmei Xu, Yixin Ma, Lianzheng Zhang
Summary: Ionic liquids have shown promise as solvents in the separation field due to their functional groups, with research focusing on the phenolate anion's effects on extracting heterocyclic N-compounds like pyrrole. The study evaluated the effectiveness of a phenolate-based ionic liquid in separating pyrrole through polarity analysis, showcasing the interaction mechanisms and selectivity for pyrrole in liquid-liquid phase behavior studies.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Multidisciplinary
Diana M. Arvelo, Manuel R. Uhlig, Jeffrey Comer, Ricardo Garcia
Summary: This study investigated the evolution of the graphite-water interface using 3D AFM and found the presence of short-lived hydration layers followed by stable molecular layers. Molecular dynamics calculations supported the experimental observations.
Article
Chemistry, Multidisciplinary
Nitesh Kumar, Aurora E. Clark
Summary: Liquid/liquid extraction is a widely used separation and purification method, and current research focuses on the transport mechanisms of solute partitioning and its relationship to solution structure at the phase boundary. Recent studies have shown that a metal salt like LiNO3 can be transported through a protrusion mechanism similar to that of H2O, highlighting the competition and complexity of solute transport mechanisms.
Article
Chemistry, Physical
Jiafu Xing, Xingyi Liu, Yasen Dai, Yanli Zhang, Zihao Su, Zhengrun Chen, Jun Gao, Yinglong Wang, Peizhe Cui
Summary: This study verifies the feasibility and effectiveness of deep eutectic solvents (DESs) for the separation of ethanol and diclofenac salt through experiments and molecular dynamics simulations, which is important for the sustainable utilization of resources.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Engineering, Chemical
Hideki Kanda, Wahyudiono, Motonobu Goto
Summary: The capillary phase separation (CPS) of two partially mixed Lennard-Jones liquids in cylindrical nanopores was investigated through molecular dynamics simulations. It was observed that solutes strongly bound to the nanopores cannot be extracted in the extraction equilibrium state. The concentration of solutes in various pore diameters was successfully predicted by a thermodynamic equation.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Chemistry, Physical
Lisa Sappl, Christos N. Likos, Andreas Zoettl
Summary: The simulation of polymer solutions requires the development of methods that accurately include hydrodynamic interactions and improve computational efficiency. This research explores a new model for simulating ring polymers and discovers a method that yields satisfying diffusion behavior by regulating the interaction intensity with the solvent.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Biochemistry & Molecular Biology
Kalyan Immadisetty, Adithya Polasa, Reid Shelton, Mahmoud Moradi
Summary: This study elucidates the activation mechanism of an engineered MscL at an atomic level and reveals the key roles of periplasmic loops and the loss of various peptide interactions in the activation process. The findings provide insights for engineering more efficient pH-sensing mechanosensitive channels.
COMPUTATIONAL AND STRUCTURAL BIOTECHNOLOGY JOURNAL
(2022)
Article
Physics, Multidisciplinary
Brian Joseph Edwards, Mohammad Hadi Nafar Sefiddashti, Bamin Khomami
Summary: This study tackles the challenge of calculating nonequilibrium entropy in polymeric liquids undergoing flow by extending equilibrium thermodynamics and applying it to nonequilibrium conditions. By introducing internal variables that quantify the internal microstructure of chain-like macromolecules and assuming an evolution of quasi-equilibrium states, the authors were able to determine the nonequilibrium entropy at different levels of coarse-graining.
Article
Mechanics
Eric S. G. Shaqfeh, Bamin Khomami
Summary: The Oldroyd-B fluid serves as the foundation for complex flow calculations and analysis of dilute polymer solutions, providing single-mode description of constitutive equations. Despite its shortcomings, the model can predict complex features of polymer solution flows effectively.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2021)
Article
Mechanics
Brian J. Edwards, M. Hadi Nafar Sefiddashti, Bamin Khomami
Summary: This retrospective covers the growth and application of atomistic simulations of alkanes and polyethylenes over a 50-year period, focusing on the development of accurate potential models and the application of molecular dynamics methodology. The authors summarize the results of simulations from the past 50 years, providing a coherent history of the subject and highlighting the significant impacts on the field of polymer rheology.
JOURNAL OF RHEOLOGY
(2022)
Article
Mechanics
Mandi Boudaghi, M. Hadi Nafar Seddashti, Brian J. Edwards, Bamin Khomami
Summary: Dissipative particle dynamics (DPD) simulations replicate the coil-stretch transition (CST) and configurational relaxation of entangled polyethylene melts observed in planar elongational flow (PEF). The width of the CST hysteresis loop is larger for longer molecule liquids. Reducing the flow Deborah number results in a two-stage relaxation process, with initial stratification followed by configurational relaxation.
JOURNAL OF RHEOLOGY
(2022)
Article
Mechanics
Jiaxing Song, Nansheng Liu, Xi-Yun Lu, Bamin Khomami
Summary: Three-dimensional elastic turbulence in Taylor-Couette flows of dilute polymer solutions has been achieved and studied through direct numerical simulations. A novel flow transition pathway from elastically dominated turbulence to solitary vortex pairs and eventually to purely elastic turbulence is observed by decreasing fluid inertia. The dominant flow features in the elastic turbulence regime are large-scale unsteady vortex pairs and small-scale traveling waves. Furthermore, the study concludes that the production of turbulent kinetic energy in purely elastic turbulence is solely due to the stochastic nature of polymer stretch/relaxation.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Environmental
Valmor F. de Almeida, Joseph F. Birdwell Jr, David W. DePaoli, Costas Tsouris
Summary: This study provides new direct experimental evidence of fluid flow in a centrifugal contactor system used in solvent extraction, revealing details of the dispersed phase state and its implications for operational modes. It highlights the importance of understanding microflow phenomena for improved performance and validates existing theories and models.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Nuclear Science & Technology
Zuolong Zhu, Dean Wang, Valmor De Almeida, Charles Forsberg, Eugene Shwageraus
Summary: In this study, a 165MW FHR core design was proposed using TRISO particle fuel, FLiBe as the primary coolant, and a three-batch fuel cycle scheme. Sensitivity analyses were performed to optimize the cycle length and neutronic parameters. Furthermore, a novel core design was proposed that can extend the fuel cycle length by approximately 45 days.
NUCLEAR SCIENCE AND ENGINEERING
(2023)
Review
Multidisciplinary Sciences
Jiaxing Song, Yabiao Zhu, Fenghui Lin, Nansheng Liu, Bamin Khomami
Summary: This retrospective aims to present a coherent history of important findings in direct numerical simulations and experiments in turbulent Taylor-Couette flow of dilute polymeric solutions in the last decade. Specifically, the article discusses the sequence of flow transitions due to an increase in fluid elasticity, including drag modification, flow structures, statistics, and mechanisms of turbulence, as well as a comparison with curvilinear and rectilinear shear flows. This article is part of a theme issue on Taylor-Couette and related flows.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Chemistry, Physical
Mahdi Boudaghi, Brian J. J. Edwards, Bamin Khomami
Summary: The evolution of shear banding under startup of shear flow was simulated for different molecular weight polyethylene melts. It was found that shear stress was dominated by segmental orientation at low shear rates, but flow-induced disentanglement resulted in the onset of chain tumbling and reduced shear stress at a critical shear rate. During shear flow startup, distinct fast and slow bands formed, consisting of more disentangled and extended chains and relatively entangled and coiled molecules, respectively. The simulation results showed temporary reverse flow, consistent with earlier experiments and theoretical results. The phenomenon of shear banding appeared to arise from flow-induced disentanglement and differential stretching of individual chains, resulting in the formation of slow and fast bands.
Article
Physics, Fluids & Plasmas
Jiaxing Song, Fenghui Lin, Yabiao Zhu, Zhen-Hua Wan, Nansheng Liu, Xi-Yun Lu, Bamin Khomami
Summary: Direct numerical simulation is used to identify the dominant flow structures in the Taylor-Couette flow of dilute polymer solutions. It is found that unsteady diwhirls and elastic waves play important roles in the formation of elastic turbulence. The interaction between these elements leads to stochastic or chaotic cycles that sustain the turbulent dynamics.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Yabiao Zhu, Zhenhua Wan, Fenghui Lin, Nansheng Liu, Xiyun Lu, Bamin Khomami
Summary: The existence of a maximum drag enhancement (MDE) asymptote at high rotation (Ro) and Weissenberg (Wi) numbers in turbulent viscoelastic spanwise-rotating plane Couette flow has been demonstrated. Above a critical Wi, drag enhancement plateaus and the MDE asymptote is realized in a broad range of Ro. The mean velocity profiles at MDE closely follow a log-law profile that has a nearly identical slope but different intercepts as a function of Ro. Moreover, the intriguing finding is that MDE occurs in the elasto-inertial turbulence (EIT) flow state and is mainly sustained by elastic forces like the MDR flow state. Hence, a universal picture of elastically induced drag modification asymptotes is emerging, where these asymptotic states are inherent to the elastically sustained EIT flow state.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Polymer Science
Mohammad Hadi Nafar Sefiddashti, Brian J. Edwards, Bamin Khomami
Summary: Atomistic simulations were performed on linear, entangled polyethylene melt under uniaxial elongational flow conditions. Flow-induced phase separation and crystallization were observed at intermediate and high flow strengths, respectively. The flow-induced crystallization occurred at a temperature higher than the quiescent melting point and remained stable after flow cessation. The results were consistent with experimental measurements of thermodynamic properties.
Article
Chemistry, Multidisciplinary
Mahshid Mokhtarnejad, Erick L. Ribeiro, Dibyendu Mukherjee, Bamin Khomami
Summary: In this study, hybrid nanocomposites (HNCs) based on manganese oxides (MnOx/Mn3O4) and reduced graphene oxide (rGO) were synthesized as active electrodes for energy storage devices. The active material was composed of MnOx/Mn3O4 nanorods and nanoparticles embedded in rGO nanosheets. The performance of the active layer was highly correlated with the MnOx/Mn3O4 to rGO ratio and the morphology of MnOx/Mn3O4 nanostructures in HNCs. Electrochemical characterizations showed that the MnOx/Mn3O4-rGO composite exhibited significantly higher specific capacitance compared to commercially available Mn3O4-graphene nanocomposites. The study has paved the way for the use of LASiS-based synthesized functional material in combination with additive manufacturing techniques for all-printed electronics with superior performance.
Article
Chemistry, Physical
Erick L. Ribeiro, Elijah M. Davis, Mahshid Mokhtarnejad, Sheng Hu, Dibyendu Mukherjee, Bamin Khomami
Summary: This study presents a facile technique for synthesizing Pt-Co bimetallic nanoparticles with superior electrocatalytic activities for oxygen reduction reaction. By adjusting the precursor concentrations, a higher degree of Pt-Co alloying can be facilitated to enhance catalytic activities while maintaining long-term stabilities in highly concentrated alkaline media. The unique configurations of the Pt-Co nanoparticles coated with a graphitic shell and supported by Co3O4-decorated carbon matrix contribute to the outstanding performances.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Ravi Pamu, Benjamin J. Lawrie, Bamin Khomami, Dibyendu Mukherjee
Summary: The study investigated wavelength-dependent plasmon-enhanced photocurrents from PSI immobilized around highly ordered Au (AuND) and Ag (AgND) nanodisks. The results showed significant enhancements in photocurrents at specific excitation wavelengths, paving the way for rational assembly of future biohybrid structures.
ACS APPLIED NANO MATERIALS
(2021)
