Article
Thermodynamics
S. Y. Guan, Z. H. Zhang, R. Wu, X. K. Gu, C. Y. Zhao
Summary: The impacts of nano-porous structures on boiling heat transfer characteristics are revealed through theoretical and modeling analysis. The results show that the boiling inception time is proportional to the void volume to solid surface area ratio, and the critical heat flux is a power law function of pore size. Molecular dynamics simulations further validate the theoretical analysis, showing a power law relation between boiling inception time and void volume to solid surface area ratio, and an exponent of 1.232 in the power law relation between critical heat flux and pore size.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Xiuliang Liu, Qifan Zou, Ronggui Yang
Summary: In this paper, a theoretical model for bubble nucleation in liquid film boiling is developed, considering transient heat conduction, evaporation at the liquid-vapor interface, and superheat requirement for bubble nucleus stability. The study establishes the ONB criterion and active microcavity size range, comparing them with pool and flow boiling.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Multidisciplinary
Yunqing Ma, Zhenjiang Guo, Qianjin Chen, Xianren Zhang
Summary: Gas bubbles are ubiquitous in electrochemical processes, particularly in water electrolysis. A deep understanding of gas bubble behaviors at the electrode surface is highly desirable due to the development of gas-evolving electrocatalysis and energy conversion technology. By combining theoretical analysis and molecular simulations, the behaviors of a single nanobubble electrogenerated at a nanoelectrode were studied, revealing various nanobubble dynamic states based on slight changes in gas solubility or solute concentration.
Article
Chemistry, Physical
Berengere Evin, Eric Leroy, Walid Baaziz, Mathieu Segard, Valerie Paul-Boncour, Sylvain Challet, Arnaud Fabre, Stephanie Thiebaut, Michel Latroche, Ovidiu Ersen
Summary: Helium-3 nanobubbles in palladium powders aged under tritium for several years were characterized using 3D analysis at the nanoscale. The nanobubbles were found to have diameters centered around 2.5 nm, and their interdistances were determined to have a mean value between 8 and 10 nm for the first time. The swelling of the aged material ranged from 8% to 18%, consistent with macroscopic measurements and modeling.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Panpan Zhao, Chaoyang Zhang, Shuai Gong
Summary: Bubble nucleation from gas cavities on gas-evolving surfaces is investigated in this study. A theoretical model is established to determine the size ranges of effective nucleation cavities and propose the criterion for the incipience of bubble nucleation. The effects of contact angle, cone angle, concentration boundary layer thickness, ambient pressure, and temperature on the nucleation cavities are explored. The results provide valuable insights for the manipulation of bubble nucleation densities and the optimal design of gas-evolving electrodes in electrochemical gas-evolving reactions.
Article
Materials Science, Multidisciplinary
Shifu Chen, Hong Lei, Hanchuang Hou, Changyou Ding, Han Zhang, Yan Zhao
Summary: Removing inclusions from molten steel using RH vacuum refining is crucial in producing high-quality steel products. Research shows that argon bubbles significantly enhance the transport and collision-coalescence of inclusions.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Materials Science, Multidisciplinary
Angshuman Podder, Kenneth S. Coley, Andre B. Phillion
Summary: A first principles-based multi-oxide inclusion (MOI) kinetic model is proposed to predict the transient evolution of oxide inclusion composition in secondary steelmaking processes. The model takes into account the thermodynamics and kinetics of different stoichiometric oxide inclusions, providing information about individual oxide particles rather than average inclusion composition. When coupled with a steel-slag model, the predictions of the MOI model show good agreement with experimental measurements, demonstrating the linkages between inclusion precipitation sequence and compositional variables.
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2023)
Article
Chemistry, Physical
Nazgol Mehrabian, Ahmad Seyfaee, Graham J. Nathan, Mehdi Jafarian
Summary: This paper presents a dynamic one-dimensional numerical model for simulating the methane pyrolysis process within a rising and pyrolysing bubble in a column of molten Ni0:27Bi0:73 catalyst. The model takes into account variations in bubble diameter and rising velocity, and solves the conservation equations of energy, mass, and momentum using the implicit Gauss-Seidel numerical method. The model considers the main parameters affecting methane pyrolysis and has been validated against experimental data.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Environmental
Brett Parkinson, Clemens F. Patzschke, Dimitrios Nikolis, Sumathy Raman, Klaus Hellgardt
Summary: Methane pyrolysis in molten salts offers a potential large-scale, low-cost, and low-CO2 production route for hydrogen. Understanding the decoupling of bubble specific surface area and volume-based CH4 reaction rates provides a basis for reaction rate modeling in industrial-scale pyrolysis reactors.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Materials Science, Multidisciplinary
Dongping Zhan, Jiaxi Wang, Luoyi Huang, Huishu Zhang
Summary: Experimental and theoretical analysis revealed the impact of slag basicity and foaming index on nitrogen capacity of slag, as well as the influence of Al2O3 content of slag on nitrogen pickup.
Article
Biochemistry & Molecular Biology
Rodion V. Belosludov, Kirill V. Gets, Ravil K. Zhdanov, Yulia Y. Bozhko, Vladimir R. Belosludov, Li-Jen Chen, Yoshiyuki Kawazoe
Summary: Using molecular dynamics, the behavior of a metastable solution of methane + water was studied for different concentrations at low pressure. The formation of hydrate-like structures was observed at certain concentrations, suggesting a new mechanism of hydrogen-bond network reorganization that leads to hydrate growth. This study reveals the importance of supersaturation and cavity arrangement in the collective process of hydrate formation.
Article
Chemistry, Physical
Seongmin Park, Mukyeong Kim, Yunha Koo, Dohyung Kang, Yohan Kim, Jinmo Park, Changkook Ryu
Summary: A numerical model of a bubble column reactor (BCR) for methane pyrolysis using molten catalysts was developed and validated. The model accurately predicted methane conversion at different temperatures and column heights and provided detailed information on key phenomena. The proposed model is valuable for reactor optimization and scale-up.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Nuclear Science & Technology
Binbin Qiu, Qingchuan Yang, Weixiong Chen, Jiping Liu, Junjie Yan
Summary: This work experimentally and theoretically studies the pressure oscillation and condensation behavior of steam bubbles at low steam mass flux. It reveals that the steam bubble condenses first, then expands and contracts, and establishes a theoretical model of heat and mass transfer in the bubble condensation process.
PROGRESS IN NUCLEAR ENERGY
(2021)
Article
Meteorology & Atmospheric Sciences
Binfan Jiang, Dehong Xia, Xiangjun Liu
Summary: The study reveals that bacteria molecules can serve as heterogeneous nucleation sources for aerosol particles, aggregating on the surfaces of inorganic aerosol precursors like sulfuric acid, forming hydrogen bonds to drive heterogeneous nucleation and contribute to the formation of secondary aerosol particles.
ATMOSPHERIC RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
Xin Yang, Liguo Zhang, Dong Cao, Xiao Han, Yuanyuan Zhang, Zhijun He
Summary: This study explored the influence of pulse current on the quantity, size, and distribution of alumina inclusions in liquid steel, as well as the action mechanism of pulse current. The results showed that the number of small alumina inclusions significantly increased after electric pulse treatment, and their particle size was concentrated at 2-5 μm. Pulse current reduced the interfacial free energy, promoted nucleation, inhibited aggregation growth, and affected the migration and distribution of inclusions.