Article
Engineering, Mechanical
Shuangxi Tang, Shayu Li, Liran Ma, Yu Tian
Summary: The development of photorheological fluids for viscosity regulation and friction control, achieved by utilizing light-induced microstructure transformation, shows promising applications in controllable lubrication and intelligent rheological fluids. Reversible friction regulation with a considerable ratio has been achieved by the alternative irradiation of near-infrared and ultraviolet light, thanks to the differences in mechanical properties and molecular structures under ultraviolet and near-infrared light.
Article
Physics, Fluids & Plasmas
Patrick Ilg
Summary: In this study, a hybrid simulation scheme was proposed to accurately model the flow behavior of ferrofluids and include small-scale fluctuations. The scheme was tested in various ways and showed good agreement with theoretical predictions.
Article
Chemistry, Physical
Hanqi Xu, Jinbo Wu, Yaying Hong, Weijia Wen
Summary: The study showed that the addition of Span surfactants can enhance the electrorheological response and colloidal stability of the suspension in a certain range. Below the optimal concentration of Span, the ER properties are improved by the increase of electrostatic interaction between particles. Above the limiting concentration, the formation of a double-layer surfactant structure leads to a weakening of the ER activity.
Article
Mathematics, Interdisciplinary Applications
Nehad Ali Shah, Jae Dong Chung, Dumitru Vieru, Constantin Fetecau
Summary: This study investigates the unsteady flows of incompressible upper-convected Maxwell fluids with shear rate memory and pressure-dependent viscosity of exponential form within a rectangular channel. Both fractional and ordinary models are compared to analyze the significance of memory effects on small values of time t. The results show that the differences between the two models become negligible for large values of time t.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Mechanics
Wangxu Li, Zhenggui Li, Wei Han, Yibin Li, Shengnan Yan, Qin Zhao, Fang Chen
Summary: This study experimentally explores the relationship between the viscosity of nano-ferrofluids and temperature, magnetic-field strength, and magnetic-field inclination. The results show that the viscosity of ferrofluids decreases with increasing temperature and increases with increasing magnetic particle content. The magnetic-viscosity phenomenon is observed, where viscosity increases under the influence of a magnetic field until reaching a saturation point.
Article
Mechanics
Peitong Li, Huibo Wang, Xiaoyu Li, Liejin Guo, Hui Jin
Summary: This paper aims to find a convenient method to calculate the friction coefficient on a flat plate in supercritical water (SCW) laminar flow using a pseudo-critical incoming state. Direct numerical simulation (DNS) is used to study the velocity profile characteristics in the SCW boundary layer and apply them to derive a semi-analytical formula for plate friction in the SCW fluid field. The method of obtaining a dimensionless parameter G(mu)* by DNS is given, and the dependence between G(mu)* and boundary conditions is derived by numerical experiments. The accuracy of this method is proved by comparing the results with DNS results.
Article
Chemistry, Multidisciplinary
Panzheng Zhou, Kevin L. Sanchez-Rivera, George W. Huber, Reid C. Van Lehn
Summary: Selective dissolution is an effective method for recycling multicomponent plastic waste by exploiting differences in polymer solubility in carefully chosen solvent systems. A computational approach was developed to predict temperature-dependent polymer solubilities, which was successfully applied to the selective dissolution of PE and EVOH.
Article
Energy & Fuels
Jipeng Xu, Su Xue, Jinli Zhang, You Han, Shuqian Xia
Summary: The study reveals the importance of using an appropriate viscosity reducer during the heavy crude oil exploitation process. By combining dissipative particle dynamics (DPD) simulation and all-atom simulation, the research successfully designs a new amphiphilic polymer as an efficient viscosity reducer by analyzing the properties of primary polymers in the oil-water system and the interaction mechanism between asphaltene and polymer molecules.
Article
Chemistry, Physical
Rohit Kumar Saw, Anshuman Singh, Neetish Kumar Maurya, Ajay Mandal
Summary: Low salinity water flooding is cost-effective and environmentally friendly, and the addition of nanoparticles and polymers can significantly increase oil recovery. The viscosity of complex chemical slugs can be increased by adding nanoparticles to polymer solutions. Low salinity water requires a lower concentration of polymer to reach the target viscosity compared to high saline formation water. The addition of nanoparticles reduces interfacial tension and contact angle, leading to higher oil recovery in low salinity water. Injection of low salinity water-based complex fluid results in incremental recovery of OOIP compared to low salinity water and conventional formation water flooding.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Polymer Science
Rishabha Malviya, Sheetal Jha, Neeraj Kumar Fuloria, Vetriselvan Subramaniyan, Srikumar Chakravarthi, Kathiresan Sathasivam, Usha Kumari, Dhanalekshmi Unnikrishnan Meenakshi, Omji Porwal, Akanksha Sharma, Darnal Hari Kumar, Shivkanya Fuloria
Summary: The rheological properties of tamarind seed polymer were characterized for potential commercialization in the food and pharmaceutical industry. The study found that the polymer solution is less sensitive to temperature changes compared to other gums, and has excellent physicochemical properties, making it a promising excipient for future drug formulation and application in the food and cosmetics industry.
Article
Chemistry, Physical
Andrzej A. Grzybowski, Alexander R. Lowe, Bernadeta Jasiok, Miroslaw Chorazewski
Summary: In this paper, thorough analyses of volumetric and viscosity data for six oils have been conducted, investigating their thermodynamic and dynamic properties. The study explores the intersection and inflection points in the temperature-pressure relations of these oils, revealing their distinct characteristics and behaviors, which contribute to a better understanding and further research on the physicochemical properties of oils.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Patrick Kreissl, Christian Holm, Rudolf Weeber
Summary: Magnetic nanoparticles couple to polymeric environments through various mechanisms, including van der Waals, steric, hydrodynamic, and electrostatic forces. This leads to interesting effects and potential applications, although the details of the coupling are often unknown. Previous work has shown that hydrodynamic coupling alone can explain observed trends in magnetic AC susceptibility spectra for spherical particles. Now, this publication focuses on the interplay of steric and hydrodynamic interactions in non-spherical particles and their coupling to a polymer suspension.
Article
Energy & Fuels
M. Elmuzafar Ahmed, Abdullah S. Sultan, Tinku Saikia, Mohamed Mahmoud, Shirish Patil, Mazen Kanj
Summary: Viscoelastic surfactants (VES) are used in enhanced oil recovery (EOR) to increase viscosity and reduce interfacial tension (IFT). This study proposes the use of chelating agents to suppress the effect of salinity and optimize the amount of VES needed for successful EOR. Experimental results show that using 6% DTPA with 1.25% VES achieves the highest viscosity, while using 4% GLDA with 1.25% VES achieves the lowest IFT. Microfluidic recovery tests demonstrate that using 4% GLDA with 1.25% VES leads to a 56% ultimate recovery. Overall, the chelating agents have been successful in reducing salinity and achieving promising recovery. Rating: 8/10.
Article
Astronomy & Astrophysics
Stefan Floerchinger, Nikolaos Tetradis, Urs Achim Wiedemann
Summary: The study focuses on how inhomogeneities of the cosmological fluid fields affect the energy density and modify the Friedmann equations, with an emphasis on observational evidence favoring evolution close to the standard growing mode. The results suggest that backreaction requires going beyond the ideal fluid approximation and may be suppressed or affected by stringent UV cutoffs in different fluid models.
Article
Physics, Mathematical
Lingxi Liu, Xin Zhong
Summary: This study focuses on the initial boundary value problem of two-dimensional nonhomogeneous micropolar fluid equations with density-dependent viscosity and non-negative density. By applying the Desjardins interpolation inequality and careful energy estimates, the global existence of a unique strong solution is proven under suitable conditions. Additionally, it is shown that the velocity and micro-rotational velocity exponentially converge to zero as time approaches infinity.
JOURNAL OF MATHEMATICAL PHYSICS
(2021)
Article
Physics, Mathematical
Michael Wang, Alexander Y. Grosberg
JOURNAL OF STATISTICAL PHYSICS
(2019)
Article
Physics, Multidisciplinary
Josh Kelly, Alexander Y. Grosberg, Robijn Bruinsma
PHYSICAL REVIEW LETTERS
(2019)
Article
Polymer Science
Yitzhak Rabin, Alexander Y. Grosberg
Biographical-Item
Physics, Multidisciplinary
M. Ya Azbel, A. F. Andreev, B. M. Bolotovskii, A. Yu Grosberg, N. M. Kreines, L. S. Levitov, L. P. Pitaevskii, V. L. Pokrovskii, E. I. Rashba, A. I. Smirnov, D. E. Khmel'nitskii, A. V. Chubukov
Editorial Material
Multidisciplinary Sciences
Alexander Y. Grosberg
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2020)
Article
Physics, Multidisciplinary
Kirill E. Polovnikov, Sergei K. Nechaev, Alexander Y. Grosberg
Summary: This study investigates the effect of curved geometry on the conformational statistics of stretched polymers. It reveals that the typical excursions of the polymer away from the surface and the curvature-induced correlation length scale follow power-law relationships, influenced by the Kardar-Parisi-Zhang (KPZ) scaling, and independent of the fractal dimension of the polymer.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Iraj Eshghi, Alexandra Zidovska, Alexander Y. Y. Grosberg
Summary: In this study, we solve a hydrodynamic model of active chromatin dynamics within a confined geometry resembling the cell nucleus. Analytical and numerical methods are used to describe the behavior of chromatin polymer driven by polar symmetric motors, both in linear response and long-term, fully nonlinear flows. The introduction of a boundary induces a specific geometry in the chromatin flows, which is described using vector spherical harmonics, simplifying the analytical and numerical approaches. Our findings show that the long-term behavior of this model in confinement is characterized by steady, transverse flows of chromatin circulating around the spherical domain, which are robust to perturbations and determined by the size of the domain. This provides further understanding of active chromatin dynamics in the cell nucleus and lays the foundation for the development of more complex models.
EUROPEAN PHYSICAL JOURNAL E
(2023)
Article
Physics, Multidisciplinary
Iraj Eshghi, Alexandra Zidovska, Alexander Y. Grosberg
Summary: This study discovers a new type of nonequilibrium phase transition in chromatin dynamics that explains the observed coherent motions. The cooperation between molecular motors tethered to chromatin drives the flow of solvent past the polymer, influencing the orientation of nearby motors. The predicted length scales match experimental results, providing insights into the effects of activity on the cell nucleus and its contents.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Iraj Eshghi, Alexandra Zidovska, Alexander Y. Grosberg
Summary: This study extends a two-fluid model to investigate the effects of three types of activity (force dipoles) on chromatin and nucleoplasm. The results show that the third type of activity dominates the flow and leads to emergent screening length scales in the system.
Article
Physics, Fluids & Plasmas
Itay Azizi, Alexander Y. Grosberg, Yitzhak Rabin
Summary: A temperature-controlled reentrant transition is observed in simulations of mixtures of small and big particles. The system undergoes a transition from a fluid mixture to a crystal of big particles in a fluid of small particles and then back to a fluid mixture as temperature increases. This solidification is driven by entropy gain of small particles, while melting is caused by enhanced interpenetration of particles at high temperature, reducing the entropic forces that stabilize the crystal.
Article
Chemistry, Physical
Michael Wang, Ketsia Zinga, Alexandra Zidovska, Alexander Y. Grosberg
Summary: The study explores how interactions between components with different levels of activity affect fluctuations of an embedded object, suggesting that hot particles may cause cold particles to accumulate on the surface of the tracer, potentially dampening its fluctuations.
Article
Physics, Multidisciplinary
Alexander Y. Grosberg
Summary: The conjecture proposes that the unknot probability for a randomly generated self-avoiding polygon has only logarithmic corrections to the known exponential law. This conjecture is supported by the numerical result of Baiesi, Orlandini, and Stella in 2010.
Article
Chemistry, Physical
Alexander Y. Grosberg, Yitzhak Rabin
Article
Physics, Fluids & Plasmas
Michael Wang, Alexander Grosberg
Article
Physics, Fluids & Plasmas
Cato Sandford, Alexander Y. Grosberg
