Article
Engineering, Civil
W. Addison-Atkinson, A. S. Chen, M. Rubinato, F. A. Memon, J. D. Shucksmith
Summary: The aim of this research is to evaluate the performance of a commonly used deterministic 1D-2D flood model, calibrated using low resolution data, against a higher resolution dataset containing flows, depths and velocity fields. The findings show that model performance was reduced as the scenario complexity increased, but most of the simulation error was < 10% (NRMSE). Additionally, the validated model with higher spatial resolution had more error compared to the lower resolution model due to less stringent calibration at lower spatial resolution. However, overall the study demonstrates the potential of using low-resolution datasets for model calibration.
JOURNAL OF HYDROLOGY
(2023)
Article
Nanoscience & Nanotechnology
Limin Zhou, Shumin Yang, Nannan Quan, Zhanli Geng, Shuo Wang, Binyu Zhao, Xingya Wang, Yaming Dong, Renzhong Tai, Jun Hu, Lijuan Zhang
Summary: This study investigates the formation of surface nanodroplets on nanostructure surfaces, demonstrating that nanostructure patterning can effectively regulate the shape, contact radius, and nucleate site of nanodroplets. Nanodroplets exhibit different wetting properties on different structures, and the physical geometry and chemical heterogeneity of the substrate affect the growth and spreading of nanodroplets.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Qiang Ma, Yi-Feng Wang, Yi-Bo Wang, Ben-Xi Zhang, Shao-Fei Zheng, Yan-Ru Yang, Duu-Jong Lee, Xiao-Dong Wang
Summary: The bouncing dynamics of water nanodroplets on superhydrophobic Pt surfaces with nanopillar arrays is comprehensively studied using molecular dynamics simulations. It is found that there are critical values of the solid fraction and pillar height to induce pancake bouncing at the moderate Weber number. A theoretical model is developed to quantitatively proclaim the dependence of nanostructure features and the critical Weber number on pancake bouncing.
APPLIED SURFACE SCIENCE
(2023)
Article
Physics, Multidisciplinary
Lianrong Zhou, Xiaoqing Hu, Yigeng Peng, Junjie Qiang, Peifen Lu, Kang Lin, Shengzhe Pan, Xiaochun Gong, Wenyu Jiang, Zhejun Jiang, Chenxu Lu, Hongcheng Ni, Cheng Jin, Ruifeng Lu, Yong Wu, Jianguo Wang, Jian Wu
Summary: We investigated the multiphoton ionization of H2 in superfluid He nanodroplets driven by femtosecond laser pulses and found that the presence of He atoms enhances the dissociation of in-droplet HH2 from lower vibrational states. Consequently, the peaks in the photoelectron energy spectrum shift to higher energies. Our simulation confirms the joint contribution of the laser field and the neighboring He atoms to the dissociation dynamics. These findings improve our understanding of the influence of the environment on light-induced ultrafast dynamics of molecules.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Eunmin Lim, Byeunggon Kim, Myung Seok Oh, Jae Bem You
Summary: Surface nanodroplets with low volume have been used for in situ chemical analysis. However, most of these nanodroplets have been formed using single organic solvents, limiting their potential applications. This study successfully formed surface nanodroplets using a green deep eutectic solvent (gDES) composed of thymol and decanoic acid, and demonstrated their effectiveness in extracting fluorescent dye and copper ions from water.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Hao Zhang, Ling Pan, Xuqing Xie
Summary: The dynamical behaviors of water nanodroplets impinging on translation and vibrating solid copper surfaces were investigated. It was found that the motion of the surfaces significantly influenced the behaviors of the droplets. On translation surfaces, water molecules rotated around the centroid of the droplet during the relative sliding stage. Moreover, the increase in vibration amplitudes hindered the spread of water nanodroplets on vibrating surfaces, while the vibration periods promoted it.
Article
Chemistry, Physical
Zixiang Wei, Jae Bem You, Hongbo Zeng, Xuehua Zhang
Summary: This work demonstrates that colorimetric chemical reactions in surface nanodroplets can alter the partitioning of acid analytes, resulting in increased acidity within the droplets. The distribution coefficient of the acid can be shifted by 3-11 times compared to the bulk solution. Such enhanced extraction and partitioning in droplets may be leveraged for highly sensitive chemical detection.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Physics, Multidisciplinary
Henrik H. Kristensen, Lorenz Kranabetter, Constant A. Schouder, Christoph Stapper, Jacqueline Arlt, Marcel Mudrich, Henrik Stapelfeldt
Summary: In this study, rubidium dimers on helium nanodroplets were doubly ionized by an intense femtosecond laser pulse, resulting in fragmentation into a pair of Rb+ ions. We demonstrate that the kinetic energy of the Rb+ fragment ions can be used to identify dimers in either the X or a state. The abundance ratio of dimers in the a and X states was found to be between 4:1 and 5:1, depending on the mean droplet size. This technique can be applied to alkali atom dimers and trimers and enable femtosecond time-resolved measurements of their rotational and vibrational dynamics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Shakul Pathak, Monojit Chakraborty, Sunando DasGupta
Summary: This study explores the physics of droplet movement under the influence of an electric field at the molecular level. Molecular simulations demonstrate that the spreading dynamics of the droplet are qualitatively similar to experimental observations. By analyzing the dynamics of droplet actuation across an electrode array, the contact line friction and its relationship with droplet velocity are determined through scaling analysis.
Article
Chemistry, Physical
Nikolai Kubochkin, Tatiana Gambaryan-Roisman
Summary: In this paper, the statics and dynamics of nanoscale droplets on elastic, infinitely thick surfaces were studied using the disjoining pressure concept. It was found that the wetting ridge evolves in a non-monotonic way in terms of its maximal height and solid angle over time.
Article
Chemistry, Physical
Shuhang Lv, Zhen Yang, Yuanyuan Duan
Summary: This study investigates the retraction kinetics of impacting nanodroplets on hydrophobic surfaces through molecular dynamics simulations. The results show that the normalized spreading radius of nanodroplets with different Weber numbers cannot collapse into a universal curve, unlike macrodroplets. The retraction rate of nanodroplets increases with Weber number and surface hydrophobicity, and a new theoretical model based on energy conservation is proposed for more accurate prediction of the retraction rate in different conditions.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Shuhang Lyu, Zhen Yang, Yuanyuan Duan
Summary: In this study, the dissipative force and sliding mode of moving nanodroplets on hydrophobic surfaces were investigated using molecular dynamics simulation. The results showed that the dissipative force had a significant effect on nanodroplets and they exhibited a combination of rolling and slipping motion on the surfaces. The effects of striped structure on the dissipative force and sliding mode were also studied.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Business, Finance
Yang Yang, Jiqiang Zhang
Summary: The study shows that a contractionary monetary policy in the US leads to an appreciation in the exchange rate. Particularly during the period of unconventional monetary policy from 2008 to 2012, monetary policy shocks had a greater negative impact on the exchange rate, supporting Dornbusch's overshooting hypothesis.
FINANCE RESEARCH LETTERS
(2021)
Article
Chemistry, Inorganic & Nuclear
Jun-Jie Hu, Yu-Guang Li, He-Rui Wen, Sui-Jun Liu, Yan Peng, Cai-Ming Liu
Summary: In this study, four isostructural lanthanide metal-organic frameworks (MOFs) with rich H-bonding were synthesized and characterized. One of the MOFs can be used as a fluorescence sensor for arginine and lysine in aqueous solution, and another MOF exhibits a significant magnetocaloric effect.
INORGANIC CHEMISTRY
(2022)
Article
Mechanics
Qiang Wang, Wei Cao, Tongyun Zhang, Cong Wang, Yingjie Wei
Summary: A numerical study is conducted to investigate the cavity collapse characteristics of a supercavitating projectile during high-speed water-exit. The results show that the cavity near the free surface gradually becomes larger with the movement of the projectile, and the presence of attitude angles leads to asymmetry in cavity collapse. The cavity on the upstream side collapses first and generates collapse pressure, while the cavity on the downstream side collapses later but generates higher collapse pressure. The asymmetry of cavity collapse strengthens with increasing attitude angles, and the time interval of collapse pressure becomes shorter close to the projectile tail.
Article
Multidisciplinary Sciences
Luuk J. Blaauw, Detlef Lohse, Sander G. Huisman
Summary: Using the Taylor-Couette geometry, we studied the impact of salt on drag reduction caused by bubbles in the flow. The drag reduction was found to decrease as the salt concentration increased, from 40% in fresh water to 15% in sea water. The presence of salts inhibited coalescence events, resulting in smaller bubbles and decreased drag reduction.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Mechanics
Somasekhara Goud Sontti, Mohsen Sadeghi, Kaiyu Zhou, Enzu Zheng, Xuehua Zhang
Summary: Pipeline transport is commonly used in the oil sand industry for conveying crushed oil sand ores and tailings. This study establishes an Eulerian-Eulerian (E-E) computational fluid dynamics model for an industrial-scale oil sand tailings pipeline. The model analysis provides valuable insights into bitumen recovery and the influence of different factors, such as particle size and bitumen droplet size, on flow characteristics in the tailing pipeline.
Article
Chemistry, Physical
Romain Billet, Binglin Zeng, James Lockhart, Mike Gattrell, Hongying Zhao, Xuehua Zhang
Summary: Switchable hydrophilicity solvents (SHSs) can transform from hydrophobic to hydrophilic forms when exposed to acidic triggers like CO2. They offer a promising alternative to volatile organic compounds for industrial solvent extraction, as they allow for greener and cheaper separation and recovery methods. Additionally, their low volatility makes SHSs less flammable and safer for large-scale extraction processes. In this study, we investigated the dynamics of drop dissolution and observed an in-drop phase separation behavior during the dissolution process of a SHS and polymer drop triggered by an acid. We found that the dissolution time is inversely related to the pH of the aqueous phase and directly related to the initial polymer concentration in the drop.
Article
Physics, Fluids & Plasmas
Christopher J. Howland, Roberto Verzicco, Detlef Lohse
Summary: Motivated by ice ablation in salt water, this study investigates the heat and salt fluxes in two-scalar vertical convection using three-dimensional direct numerical simulations. The salinity field drives the convection while heat is transported as passive scalar. The diffusivity ratio of heat and salt affects the scalar fluxes, with heat transport determined by a turbulent Prandtl number of Prt approximate to 1 and double-diffusive effects being negligible.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Computer Science, Interdisciplinary Applications
Youssef Saade, Detlef Lohse, Daniel Fuster
Summary: We extend the all-Mach solver proposed by Fuster and Popinet (2018) [1] to account for heat diffusion between two compressible phases. By solving a coupled system of equations for pressure and temperature, our code improves the robustness and accuracy of the solver compared to classical explicit discretization schemes. Several test cases are used to validate the implementation, including comparisons with spectral methods and analytical solutions. The code is also applied to the study of sonoluminescent bubbles, Rayleigh collapse, and bubble collapse near a rigid boundary, demonstrating the importance of thermal effects in these phenomena.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Mechanics
Pierre Chantelot, Detlef Lohse
Summary: Gas film and nonlinear advection are two physical mechanisms affecting the rebounding of impacting drops. We reveal the dominance of the nonlinear advection regime through impacts on superheated surfaces. By measuring the gas film thickness under impacting drops, we provide evidence for the transition from the surface tension to the nonlinear inertia dominated regime.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Chemistry, Multidisciplinary
Kaiyu Zhou, Vincent Maugard, Wenming Zhang, Joe Zhou, Xuehua Zhang
Summary: Recent developments in ultrafine bubble generation have opened up new possibilities for applications in various fields. This study investigated the effects of substances in water on the size distribution and stability of microbubbles generated by a nanobubble generator. The results showed that air injection generated more microbubbles (<10 μm) compared to CO2 injection. Increasing detergent concentration led to a rapid increase in the number of microbubbles generated, while salts in water did not significantly affect the number or size distribution of bubbles. The presence of oil in water increased the intensity signal and resulted in bubbles coated with an oil layer.
Article
Physics, Fluids & Plasmas
Yuki Wakata, Ning Zhu, Xiaoliang Chen, Sijia Lyu, Detlef Lohse, Xing Chao, Chao Sun
Summary: In this study, we investigate the Leidenfrost temperature for hot solid substrates with different thermal diffusivities and surface roughnesses. A phenomenological model is developed based on experimental data, which considers the thermal diffusivity of the solid substrate and establishes the relationship between surface roughness and vapor film thickness. The generality of this model is supported by experimental data for various liquids and solid substrates, providing a theoretical prediction of the Leidenfrost temperature and a comprehensive understanding of the Leidenfrost effect.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
You-An Lee, Detlef Lohse, Sander G. Huisman
Summary: We experimentally investigate the early-stage scalar mixing and transport with solvent exchange in a quasi-2D jet. Different modes of fluid supply, continuous injection and finite volume injection, are studied to analyze the starting jet and puff behaviors. The results show that the lack of continuous fluid supply in the puff leads to different characteristics in transport, entrainment, mixing, and nucleation.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Mechanics
Nikolas O. Aksamit, Robert Hartmann, Detlef Lohse, George Haller
Summary: Mathematical developments in the theory of objective coherent structures have improved our understanding of the material organization of complex fluid flows. However, there is limited investigation into these objectively defined transport barriers in 3-D unsteady flows with complicated spatiotemporal dynamics. Our study utilizes simulations to uncover the interplay between different types of barriers in turbulent rotating Rayleigh-Bénard convection.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Jochem G. Meijer, Yanshen Li, Christian Diddens, Detlef Lohse
Summary: When an immiscible oil drop is immersed in a stably stratified ethanol-water mixture, it undergoes a transition from levitating to bouncing due to the oscillatory instability of the Marangoni flow on the drop's surface. The bouncing characteristics of the drop, such as jumping height and rising and sinking time, are studied in relation to the control parameters of drop radius, stratification strength, and drop viscosity. Experimental observations are backed by a simplified dynamical analysis and numerical simulations to verify the drag coefficients.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Rui Yang, Christopher J. Howland, Hao-Ran Liu, Roberto Verzicco, Detlef Lohse
Summary: The presence of salt affects the melt rate and shape evolution of ice in seawater. Numerical simulations and experiments are used to study ice melting in saline water. The melt rate of ice decreases and then increases with increasing salt concentration due to the competition between salinity-driven and temperature-driven buoyancy. A theoretical model based on force balance predicts the minimal salt concentration for ice melt rate, consistent with the data. Interplay between phase transitions and double-diffusive convective flows is revealed.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Fluids & Plasmas
Pallav Kant, Cesar Pairetti, Youssef Saade, Stephane Popinet, Stephane Zaleski, Detlef Lohse
Summary: We use experiments and numerical computations to study the fluid mechanical processes involved in the generation of bioaerosols during forceful respiratory maneuvers like coughing or sneezing. By performing analogous experiments on a cough machine, we observe the disintegration of a thin liquid film into small droplets and identify that aerosol generation is mediated by the formation of inflated baglike structures. The breakup of these bags is triggered by retracting holes on the surface, and the dynamics and stability of the liquid rims bounding these holes play a key role in the cascade from inflated bags to droplets. The viscosity of the fluid also affects the fragmentation process, with more viscous films producing smaller droplets.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Nanoscience & Nanotechnology
Muzammil Kuddushi, Xiaoyi Deng, Jyotsnamayee Nayak, Sidi Zhu, Ben Bin Xu, Xuehua Zhang
Summary: Modern healthcare engineering requires a wound dressing solution with outstanding features such as biological compatibility, mechanical strength, and antibacterial properties. We have developed a unique hydrogel technology consisting of charged biopolymers and a synthetic polymer. The hydrogel film dressings showed excellent stretchability, water swelling ratio, mechanical strength, self-healing abilities, hemostasis properties, antibacterial effects, and cell viability, making them promising biomaterials for wound dressing applications.
ACS APPLIED BIO MATERIALS
(2023)
Article
Environmental Sciences
Yanan Li, Qiuyun Lu, Mohamed Gamal EI-Din, Xuehua Zhang
Summary: This study demonstrates a simple strategy to fabricate surface-bound catalytic nanoparticles for water treatment by using in-situ fabrication from surface nanodroplets. The photocatalytic performance of ZnO nanocaps immobilized on curved glass surface showed good degradation performance for contaminants under solar irradiation.
Article
Chemistry, Physical
Yiping Yin, Zhe Wang, Hua Zou
Summary: This study presents a novel method for preparing dimpled polymer-silica nanocomposite particles using interfacial swelling-based seeded polymerization. The optimized conditions allow for a relatively high percentage of dimpled particles to be achieved.
Article
Chemistry, Physical
Brenden D. Hoehn, Elizabeth A. Kellstedt, Marc A. Hillmyer
Summary: Porous materials with nanometer-scale pores have important applications as nanoporous membranes. In this study, ABA triblock copolymers were used as precursors to produce nanoporous polymeric membranes (NPMs) in thin film form by degrading the end blocks. Polycyclooctene (PCOE) NPMs with tunable pore sizes were successfully prepared using solvent casting technique. Oxygen plasma etching was employed to improve the surface porosity and hydrophilicity of the membranes. This study provides a straightforward method to produce tough NPMs with high porosity and hydrophilic surface properties.
Article
Chemistry, Physical
Vladislav S. Petrovskii, Stepan I. Zholudev, Igor I. Potemkin
Summary: This article investigates the behavior of linear and ring polypeptide chains in aqueous solution and explores the properties of the complexes formed by these chains with oppositely charged surfactants. The results demonstrate that the complexes of linear supercharged unfolded polypeptides and the corresponding surfactants exhibit impressive adhesive properties.
Article
Chemistry, Physical
Merve Cevik, Serkan Dikici
Summary: Cardiovascular diseases are a leading cause of death globally, and vascular grafts are a promising treatment option. This study focuses on tissue-engineered vascular grafts (TEVGs) using decellularized parsley stems as a potential biomaterial. The decellularized parsley stems showed suitable properties for TEVGs, providing a suitable environment for human endothelial cells to form a pseudo endothelium. This study showcases the potential of using parsley stems for TEVGs.
Article
Chemistry, Physical
Gustavo A. Vasquez-Montoya, Tadej Emersic, Noe Atzin, Antonio Tavera-Vazquez, Ali Mozaffari, Rui Zhang, Orlando Guzman, Alexey Snezhko, Paul F. Nealey, Juan J. de Pablo
Summary: The optical properties of liquid crystals are typically controlled by electric fields. In this study, we investigate the effects of microfluidic flows and acoustic fields on the molecular orientation and optical response of nematic liquid crystals. We identify several previously unknown structures and explain them through calculations and simulations. These findings hold promise for the development of new systems combining sound, flow, and confinement.
Article
Chemistry, Physical
Xinjun Wu, Xin Guan, Shushu Chen, Jiangpeng Jia, Chongyi Chen, Jiawei Zhang, Chuanzhuang Zhao
Summary: This research presents a novel shape memory hydrogel with a remodelable permanent shape and programmable cold-induced shape recovery behavior. The hydrogel is prepared using specific treatment methods to achieve shape fixation by heating and shape recovery by cooling. Additionally, deformable devices can be obtained by assembling hydrogel blocks with different concentrations.
Article
Chemistry, Physical
Rebecca Hengsbach, Gerhard Fink, Ulrich Simon
Summary: This study examines the properties of DNA functionalized pNipmam microgels and pure pNipmam microgels at different concentrations of sodium chloride and in PBS solutions using temperature dependent H-1-NMR measurements. The results show that DNA modification affects the volume phase transition temperature and the addition of salt and PBS further enhances this effect.
Article
Chemistry, Physical
Ningyi Li, Junhong Li, Lijingting Qing, Shicheng Ma, Yao Li, Baohui Li
Summary: This paper investigates the self-assembly behavior of colloids with competing interactions under spherical confinement and finds that different ordered structures can be formed under different sized spherical confinements. Moreover, more perforated structures are formed in smaller spheres.
