Article
Energy & Fuels
Olubukola Ishola, Javier Vilcaez
Summary: The study utilized a stochastic pore-scale simulation approach to improve permeability prediction accuracy, generating hundreds of 3D pore microstructures for better estimation. Machine learning techniques were employed to reduce the number of required pore-scale simulations significantly, resulting in accurate permeability estimations.
Article
Construction & Building Technology
Pakpoom Limtong, Ravi A. Patel, Yuya Takahashi, Tetsuya Ishida
Summary: This study compares experimentally obtained hardened cement paste microstructures with virtual microstructures generated by two hydration models. It is found that none of the virtual microstructures can fully capture the actual microstructural features, and there are differences in pore structure between the two hydration models, which affect the output diffusivity.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Mechanics
Fatemeh Molaei, Amin Hamed Mashhadzadeh, Christos Spitas, Mohammad Reza Saeb
Summary: This study compares the fracture behavior and mechanical properties of diamond and gold in different conditions. Diamond shows brittle fracture mode while gold exhibits plastic deformation. Temperature has less impact on the fracture strength of diamond and more significant impact on gold. The mechanical properties of bicrystalline gold are lower than ideal monocrystalline gold.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Chemistry, Multidisciplinary
Fangsheng Wu, Xiao Jin, Zhou Guan, Jiaping Lin, Chunhua Cai, Liquan Wang, Yongsheng Li, Shaoliang Lin, Pengfei Xu, Liang Gao
Summary: The study reports a novel phenomenon of nanopore formation achieved through the insertion of polymeric nanotoroids into cellular membranes. Experimental confirmation of this unique biophysical phenomenon and the deepening of understanding on membrane nanopore phenomenon may assist in the design of advanced pore-forming materials.
Article
Environmental Sciences
Shuaibing Song, Ming Li, Qingyi Tu, Anying Yuan, Zhenhua Jiao, Pan Li, Wenxin Qian, Hewu Liu, Nan Xu
Summary: An improved universal fusion algorithm for constructing three-dimensional multiscale porous media was proposed and successfully applied to carbonate rock, sandstone, and coal, with their absolute permeability calculated using the finite element method. The results showed that the improved fusion algorithm effectively reduced pore bias and maintained good pore interconnectivity, with a wider pore size distribution interval and closer absolute permeability values to laboratory measurements compared to the existing algorithm.
WATER RESOURCES RESEARCH
(2021)
Article
Computer Science, Interdisciplinary Applications
Barry L. Nelson, Alan T. K. Wan, Guohua Zou, Xinyu Zhang, Xi Jiang
Summary: This paper proposes the use of frequentist model averaging to create input models that better represent the true, unknown input distribution, thereby reducing model risk. The method is built on standard input modeling practices, is not computationally burdensome, requires no change in how the simulation is executed, and is available on the Comprehensive R Archive Network (CRAN). The approach is supported by theoretical and empirical evidence.
INFORMS JOURNAL ON COMPUTING
(2021)
Article
Materials Science, Multidisciplinary
Sho Hayakawa, Juntan Li, Jaswanth Bommidi, Haixuan Xu
Summary: In this study, atomistic simulations are used to investigate the dislocation properties of NiCo and NiFe alloys. It is found that the core energy of a screw dislocation is lower than that of an edge dislocation in both alloys. The compositional dependence of core width is not relevant to that of Peierls stress, contrary to the classical Peierls-Nabarro model. The results provide fundamental insights into the dislocation properties of these alloys and their underlying deformation mechanisms.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Qing Peng, Zhiwei Ma, Shixian Cai, Shuai Zhao, Xiaojia Chen, Qiang Cao
Summary: The process parameters for the growth of AlGaN thin films have been investigated via molecular dynamics simulations. The effects of annealing temperature, heating and cooling rate, number of annealing rounds, and high temperature relaxation on the quality of AlGaN thin films have been examined. Optimum thin film with high quality is achieved at a thermal annealing temperature of 4600 K and six rounds of annealing.
Article
Multidisciplinary Sciences
Martin Kroll, Timo Schmalofski, Holger Dette, Rebecca Janisch
Summary: By using a sequential design of experiment scheme, this study proposes a method to combine the generation and learning process of data for improving data-based material design. The application focuses on predicting the energy of grain boundaries based on their geometric degrees of freedom. This technique can automatically discover unknown deep cusps with minimal data points, which is advantageous for applications with strong localized fluctuations in unknown functions.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Materials Science, Multidisciplinary
Wei Li, Petra Bacova, Alireza F. Behbahani, Craig Burkhart, Patrycja Polinska, Vagelis Harmandaris, Manolis Doxastakis
Summary: Surface modification with silane effectively modulates chain conformations near the silica surface, showing that silane presence weakens the dynamic slowing down at the interface, with the grafting density and agent chain length playing key roles.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Astronomy & Astrophysics
Abinash Kumar Shaw, Somnath Bharadwaj, Debanjan Sarkar, Arindam Mazumdar, Sukhdeep Singh, Suman Majumdar
Summary: This study examines the dependence of the bispectrum on the size and shape of the triangle, introducing a parameterization that separates size and shape dependence, and implementing a fast estimator. Validation using non-Gaussian fields and linear redshift space distortion demonstrates close agreement between estimated and analytical bispectrum values.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Automation & Control Systems
Anne G. Balter, Antoon Pelsser
Summary: This article discusses the importance of recognizing the limitations of models in financial and economic decision-making under uncertainty. The authors propose a set of clear alternative models and derive a quantitative upper limit on the uncertainty set using probability measures. The research also establishes a relationship between the ambiguity bound and numerical values on several divergence measures.
SYSTEMS & CONTROL LETTERS
(2021)
Article
Polymer Science
Malak Barakat, Hilal Reda, Anthony Chazirakis, Vagelis Harmandaris
Summary: In this study, the mechanical properties of graphene-based polymer nanocomposites were investigated using a hierarchical multiscale approach. By combining atomistic simulations and continuum mechanics, the effective Young's modulus and Poisson's ratio were calculated at different scales. A continuum three-phase micro mechanical finite element model was developed to predict the overall mechanical behavior of the structure.
Article
Environmental Sciences
T. J. Lawrence, S. J. Carr, J. A. T. Wheatland, A. J. Manning, K. L. Spencer
Summary: Flocculated cohesive suspended sediments (flocs) play a crucial role in aquatic environments, but accurate measurement of their physical properties, including porosity, is challenging. In this study, a novel processing and analysis protocol using μCT was employed to directly quantify porosity in natural sediment flocs. The results revealed the complexity of floc pore space and identified effective and isolated pore spaces, providing new insights into the hydraulic functioning of floc porosity. Current methodological approaches were found to overestimate floc porosity by approximately 30%.
JOURNAL OF SOILS AND SEDIMENTS
(2022)
Article
Biochemistry & Molecular Biology
Yueyue Jing, Yilin Lv, Jingya Ye, Longfang Yao, Liwen Chen, Lan Mi, Yiyan Fei, Yao Yu, Biao Dong, Hong Lv, Jiong Ma
Summary: A new method has been developed to measure the export flux of mRNA in single live cells using snapshot images, allowing for direct monitoring of gene behavior and understanding of gene regulation. The technique has been validated in HeLa cells and yeast cells, showing its noninvasive nature and potential for research in gene expression.
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
(2021)
Article
Construction & Building Technology
Muhammad Hamza, Zhihong Nie, Mubashir Aziz, Nauman Ijaz, Muhammad Faizan Ameer, Zain Ijaz
Summary: This article presents a comprehensive study on the efficacy of xanthan gum as a green construction material in treating problematic expansive subgrade. The results showed a reduction in soil plasticity with the increase in xanthan gum content and aging period. At 1.5% xanthan gum content, the treated soil exhibited significantly improved strength. Microstructural studies indicated that the bridging of soil particles with xanthan gum-hydrogel formation contributed to strength development.
ROAD MATERIALS AND PAVEMENT DESIGN
(2023)
Article
Thermodynamics
Qianhui Wu, Lei Ding, Lei Zhang, Jijiang Ge, Mohammad Azizur Rahman, Dominique Guerillot, Ioannis G. Economou
Summary: The feasibility of using polymer enhanced foam (PEF) for enhanced oil recovery (EOR) in strongly oil-wet and heterogeneous carbonate reservoirs was investigated. The study focused on the effect of polymer type, flow rate, and brine composition on the foam strength and stability. It was found that adding an associative polymer or a nonionic polymer to the foam greatly enhanced its strength and stability, leading to significant improvements in oil recovery efficiency. The study highlights the importance of the interactions between the polymer and surfactant in PEF behavior.
Article
Thermodynamics
Nefeli Novak, Georgios M. Kontogeorgis, Marcelo Castier, Ioannis G. Economou
Summary: In this study, the eSAFT-VR Mie equation of state is extended to low relative permittivity, non-aqueous solutions. Different relative permittivity relations and approaches for the characteristic diameters are investigated. Results show that a mole fraction based mixing rule for the relative permittivity yields the best extrapolation from aqueous to non-aqueous solutions.
FLUID PHASE EQUILIBRIA
(2023)
Article
Chemistry, Physical
Giannis D. Savva, Raz L. Benson, Ilektra A. Christidi, Michail Stamatakis
Summary: Motivated by the need for large-scale kinetic Monte Carlo (KMC) simulations, this study extends previous work in benchmarking a distributed-computing, on-lattice KMC approach. By combining the graph-theoretical KMC framework with the Time-Warp algorithm, the software package Zacros divides the lattice into subdomains to achieve parallel simulations. The key parameters of the Time-Warp algorithm, such as the state saving interval and the global virtual time computation interval, are explored to optimize the performance of the simulations. These findings are crucial for maximizing the efficiency of Zacros or other distributed KMC software, allowing for accurate meso-scale simulations of heterogeneous catalysis.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Bryan K. Y. Ng, Cherie C. Y. Wong, Wentian Niu, Hector P. Garcia, Yiyang Li, Ping-Luen Ho, Winson C. H. Kuo, Robert A. Taylor, Keita Taniya, Qi Wei, Mingjie Li, Michail Stamatakis, Shik Chi Edman Tsang
Summary: 2D-layered transition metal chalcogenides are semiconductors with a wide range of opto-electronic applications. By creating new heterojunction assemblies from layer-by-layer restacking, their electronic properties can be modified, but the lack of specific interaction between layers could lead to phase segregation. In this study, MoS2 and In2Se3 were exfoliated into monolayer-containing colloids using a chemical method with n-BuLi. The selective leaching of bulky Se atoms from In2Se3 during Li treatment resulted in positively charged surface monolayers, while the strong polarization of Mo-S with moderate S leaching resulted in a negatively charged surface. Specific interlayer electrostatic attraction during selective assembly gave a controllable atomic AB-type layer stacking, as supported by various characterization techniques. This simple and inexpensive bottom-up solution method enables the tailor-made fabrication of a photocatalyst assembled from layers for high activity in photo water splitting.
MATERIALS CHEMISTRY FRONTIERS
(2023)
Article
Thermodynamics
Ilias K. Nikolaidis, Romain Privat, Jean-Noel Jaubert, Ioannis G. Economou
Summary: This study assesses the performance of the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state (EoS) using various mixing rules and regression parameters, based on a high-quality reference database. The model's ability to qualitatively reproduce experimental data is quantified using a performance indicator. The effects of induced-association and cross-association on the EoS are investigated, and the final optimized EoS is determined. The average mark for the optimized EoS is 9.3/20.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2023)
Biographical-Item
Chemistry, Physical
Edward J. Maginn, Ioannis G. Economou, Randall Q. Snurr, Arup K. Chakraborty
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Angel D. Cortes Morales, Nikolaos Diamantonis, Ioannis G. Economou, Cornelis J. Peters, J. Ilja Siepmann
Summary: The behavior of binary systems containing a low-boiling compound and a high-boiling compound near the critical point of the low-boiling compound can be unexpected. Increasing the pressure near the critical temperature of the low-boiling compound and for compositions rich in the low-boiling compound may result in the crossing of dew-point and bubble-point curves multiple times. This phenomenon, known as double retrograde vaporization, has implications in oil field operations and gas transport through pipelines, but the underlying reasons for its occurrence are not well understood. Monte Carlo simulations were conducted to provide molecular insights into the fluid properties associated with double retrograde vaporization using the united-atom version of the TraPPE force field for a methane/n-butane mixture.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Noura Dawass, Manolis Vasileiadis, Loukas D. Peristeras, Konstantinos D. Papavasileiou, Ioannis G. Economou
Summary: Shale gas production is a rapidly growing sector in the oil and gas industry, and accurate prediction of its adsorption and transport is crucial for estimating production capacity. This study used molecular simulations to investigate the adsorption and diffusion of methane, ethane, and shale gas in a composite pore model representing heterogeneous shale formations. The addition of an inner slit pore significantly increased the adsorption of methane, and the saturation of the composite pore with methane occurred at a higher pressure than ethane. Carbon dioxide adsorption was not strongly affected by pressure, and its affinity to kerogen micropores was observed in all conditions. Diffusion coefficients were found to increase with the width of the empty slab inside the composite pore. The results provide insights into the adsorption mechanisms occurring inside the pore.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Sai Sharath Yadavalli, Glenn Jones, Raz L. Benson, Michail Stamatakis
Summary: Methane steam reforming is an important industrial process for hydrogen production, but suffers from coking due to methane cracking. In this study, an Ab initio KMC model was developed to understand the terminal state of graphene/coke during methane cracking on Ni(111). By systematically assessing the influence of effective cluster interactions, the model predicts significant changes in the terminal state morphology with increasing fidelity of the cluster expansions. High-fidelity simulations reveal C-CH island/rings that are disconnected at low temperatures but encapsulate the Ni(111) surface at high temperatures.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Multidisciplinary Sciences
Giannis D. Savva, Raz L. Benson, Ilektra-Athanasia Christidi, Michail Stamatakis
Summary: Kinetic Monte Carlo (KMC) simulations are important in catalysis studies, but the accessible length- and time-scales have limited their use. A distributed lattice-based approach for exact simulations of catalytic kinetics is developed, enabling the handling of complex interactions within large lattices. The approach is benchmarked with a Brusselator system and demonstrates significant speedup compared to traditional KMC methods.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Energy & Fuels
Azeezat Ali, David R. Cole, Alberto Striolo
Summary: Chemical additive inspired by cyclohexane promotes the aggregation of asphaltene molecules in toluene, forming small colloidal particles. The study used molecular dynamics simulations to investigate the behavior of model island and archipelago asphaltene structures in the presence of the additive. The results show that the additive promotes stacking of asphaltenes, resulting in more compact aggregates.
Review
Engineering, Chemical
Nefeli Novak, Georgios M. Kontogeorgis, Marcelo Castier, Ioannis G. Economou
Summary: This study focuses on the mixed-solvent electrolyte solutions and addresses the mean ionic activity coefficients, vapor-liquid equilibrium, and liquid-liquid equilibrium. The existing models and equations of state for electrolyte systems are reviewed, with emphasis on physical and electrolyte terms, relative static permittivity, and parameterization. A predictive model, eSAFT-VR Mie, is used to predict the activity coefficients, vapor-liquid equilibrium, and liquid-liquid equilibrium without any new adjustable parameters. The model shows excellent performance in predicting the activity coefficients and vapor-liquid equilibrium, while the prediction for liquid-liquid equilibrium is more challenging but has potential with accurate composition capturing.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Hector Prats, Michail Stamatakis
Summary: Transition metal carbides (TMCs) are proposed as catalysts and supports for small metal particles to replace expensive late transition metals as heterogeneous catalysts. High-throughput screening based on density functional theory shows that TMCs break the limitations that the linear scaling relations impose to transition metals.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Layla Bou Tannous, Mirella Simoes Santos, Zheng Gong, Paul-Henri Haumesser, Anass Benayad, Agilio A. H. Padua, Audrey Steinberger
Summary: The interfacial structure of room temperature ionic liquids (ILs) on different substrates and water content conditions has been studied, revealing that the presence of water contamination can affect the formation of bilayer structures in ILs.