Editorial Material
Nanoscience & Nanotechnology
Xiao Li, Jack Ng
Summary: Nano-antennas can generate optical recoil forces to independently control the direction and rotation of small objects.
NATURE NANOTECHNOLOGY
(2022)
Article
Mechanics
Nang X. Ho, Truong V. Vu, Vinh T. Nguyen, Cuong T. Nguyen, Hung V. Vu
Summary: This study provides a numerical investigation of the contraction of a two-layered compound filament and finds that the presence of inner and outer filaments inside the compound filament leads to different types of droplets formed during the contraction process. The breakup modes and mechanisms of the compound filament are affected by various parameters such as inner and outer aspect ratios, the Ohnesorge number, the interfacial tension ratio, and the viscosity ratios, resulting in different regime diagrams of breakup and non-breakup.
Article
Astronomy & Astrophysics
Eric Braaten, Hans-Werner Hammer
Summary: A nonrelativistic unparticle is an excitation created by an operator with a definite scaling dimension in a nonrelativistic field theory with approximate conformal symmetry. The rate of point production for an unparticle depends on its total energy with a power-law exponent determined by its scaling dimension. Using the exact result for the 3-point function of primary operators in a nonrelativistic conformal field theory, we derive the contribution to the point production rate of an unparticle from its decay into another unparticle recoiling against a particle. In the case of a broken conformal symmetry by a large positive scattering length, the exponent of the energy in the point production rate is deduced for the loosely bound two-particle state recoiling against a particle with large relative momentum.
Article
Chemistry, Physical
Cody D. Schimming, Jorge Vinals
Summary: We study two dimensional tactoids in nematic liquid crystals using a Q-tensor representation. We find that anisotropic anchoring and Frank-Oseen elasticity affect the morphology of the nematic-isotropic domains, with differences in interface thickness depending on the relative orientation of the director at the interface. Interfaces become biaxial when anisotropy is introduced. Surface defects induced by boundary topology become sharper with increasing elastic anisotropy in negative tactoids. By studying the energy landscape, we find that surface defects do not represent the minimum energy configuration in positive tactoids, instead yielding semi-bipolar director configurations with non-circular interface morphology due to the interplay between Frank-Oseen elasticity and anisotropic anchoring. Furthermore, the evolution of the director configuration in growing tactoids is highly sensitive to the anisotropic term in the free energy, and minimum energy configurations may not represent kinetically obtained tactoids at long times.
Article
Chemistry, Physical
Shivam Gupta, Bidisha Bhatt, Meenaxi Sharma, Krishnacharya Khare
Summary: The static wetting behavior of drops on surfaces with thin lubricating films is different from that on solid surfaces. It is difficult to predict the apparent contact angles of such drops due to the slow dynamics of the wetting ridge. In this study, the quasi-static wetting morphology of sinking drops on lubricated surfaces is numerically computed using Surface Evolver, and the results agree well with experiments. The apparent contact angles are found to be significantly influenced by the lubricant thickness and substrate wettability compared to other parameters.
Article
Engineering, Chemical
Xin Huang, Xiaoming Luo, Yunrui Han, Weidong Li, Yuekun Lai, Lin Teng
Summary: The deformation and breakup behaviors of droplets containing polymer were investigated to understand the mechanism of electric field collapse during the treatment of emulsion containing polymer. The results showed that the electric field collapse process caused by droplet breakup consists of three steps, and the increase of polymer concentration strengthens the Joule heating effect.
Article
Polymer Science
Baoji Hu, Hong Xia, Fan Liu, Qing-Qing Ni
Summary: This study innovatively endowed thermoplastic epoxy (TEP) with heat-stimuli controllability of shape memory function by adding PEG in an environmentally friendly way, solving the problems of difficult melt processing and uncontrollable stimuli temperature for TEP.
Article
Multidisciplinary Sciences
Emma J. Banks, Mauricio Valdivia-Delgado, Jacob Biboy, Amber Wilson, Ian T. Cadby, Waldemar Vollmer, Carey Lambert, Andrew L. Lovering, R. Elizabeth Sockett
Summary: Peptidoglycan hydrolases play an important role in shaping the cell morphology of bacteria. In this study, a peptidoglycan hydrolase was found in the predatory bacterium Bdellovibrio bacteriovorus, which is responsible for generating cell curvature. This enzyme invades prey bacteria, replicates within them, and alters its own cell wall to change its shape. This finding is significant for understanding bacterial morphology diversity and predatory fitness.
NATURE COMMUNICATIONS
(2022)
Article
Astronomy & Astrophysics
Tatsuya Akiba, Ann-Marie Madigan
Summary: The gravitational-wave recoil kicks from merging supermassive black hole binaries can significantly affect the surrounding stellar population. In this study, the dynamic and kinematic properties of nuclear star clusters after a recoil kick are investigated, revealing unique signatures that can aid in the observational search for recoiling supermassive black holes.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
G. Castignani, E. Meyer, M. Chiaberge, F. Combes, T. Morishita, R. Decarli, A. Capetti, M. Dotti, G. R. Tremblay, C. A. Norman
Summary: This study reports high-resolution molecular gas observations of the 3C 186 system. The results show the presence of a large reservoir of molecular gas that is co-spatial with the host galaxy and likely associated with a rotating disk-like structure. The study confirms the spatial offset between the galaxy's gas reservoir and the continuum emission of the quasi-stellar object (QSO), as well as the spectral offset with respect to the redshift of the broad line region. The findings support the hypothesis that the QSO is a kicked super-massive black hole resulting from a strong gravitational wave recoil after the merger of their host galaxies.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Engineering, Chemical
Justin J. Nijdam, Deepa Agarwal, Ben S. Schon
Summary: The study evaluated the dimensional stability window of food inks for 3D food printing based on rheological measurements of their rigidities, providing guidance on likely stability of 3D-printed food items. The screening method shows promise for accelerating the development of 3D-printing food inks by narrowing down potential candidates before printing tests begin. No correlation was found between rheological properties and filament quality of the food inks, as hardening times for molten ink filaments varied significantly.
JOURNAL OF FOOD ENGINEERING
(2021)
Article
Computer Science, Software Engineering
Xavier Chermain, Cedric Zanni, Jonas Martinez, Pierre-Alexandre Hugron, Sylvain Lefebvre
Summary: We propose a method for 3D printing surfaces with a prescribed varying field of anisotropic appearance using standard fused filament fabrication printers. By controlling the direction of deposition paths, we can achieve a visual anisotropic appearance similar to brushed metal. Our algorithm for optimizing oriented, cyclic paths outperforms existing approaches in terms of efficiency, robustness, and result quality. We demonstrate the effectiveness of our technique in conveying anisotropic appearance on challenging test cases, including patterns and photographs reinterpreted as anisotropic appearances.
ACM TRANSACTIONS ON GRAPHICS
(2023)
Article
Engineering, Chemical
Xiaofeng Jiang, Shixing Chen, Enle Xu, Xianliang Meng, Guoguang Wu, Huai Z. Li
Summary: This study investigates the downhill motion of liquid drops and liquid marbles using two distinct particle-laden interfaces. It is found that liquid marbles have a lower velocity than liquid drops but a higher maximum aspect ratio, indicating different interactions due to particles present on different surfaces.
Article
Chemistry, Multidisciplinary
Meng Wang, Ying Song, Hari Krishna Bisoyi, Jian-Feng Yang, Li Liu, Hong Yang, Quan Li
Summary: This study prepared the first two-way shape-memory liquid crystal elastomer (LCE)-based aerogel, which possesses a liquid crystal phase and good orientation, allowing reversible shape deformation during heating/cooling cycles.
Article
Astronomy & Astrophysics
Kayhan Gultekin, Sarah Burke-Spolaor, Tod R. Lauer, T. Joseph W. Lazio, Leonidas A. Moustakas, Patrick Ogle, Marc Postman
Summary: The study used Chandra X-ray observations to search for evidence of a recoiling black hole in the brightest cluster galaxy in Abell 2261, but did not find any point source X-ray emission exceeding that of the cluster gas.
ASTROPHYSICAL JOURNAL
(2021)
Article
Multidisciplinary Sciences
Ting-Pi Sun, Franco Alvarez-Novoa, Klebbert Andrade, Pablo Gutierrez, Leonardo Gordillo, Xiang Cheng
Summary: The researchers develop a high-speed stress microscopy method to measure the dynamic properties of drop impact responsible for erosion. They observe the rapid propagation of stress maxima underneath impacting drops and the formation of surface waves on impacted substrates.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Valentina Hernandez, Davor Ibarra, Johan F. Triana, Bastian Martinez-Soto, Matias Faundez, Diego A. Vasco, Leonardo Gordillo, Felipe Herrera, Claudio Garcia-Herrera, Alysia Garmulewicz
Summary: This article focuses on agar biopolymer films and their potential for developing biodegradable packaging. The study analyzes the mechanical performance of agar-glycerin biopolymer films using a Design of Experiments approach and demonstrates that by systematically varying the quantity of agar and glycerin, comparable tensile properties can be achieved. The results provide valuable data for optimization efforts and support the development of data-driven design and fabrication workflows.
Article
Physics, Multidisciplinary
Benjamin Foster, Nicolas Verschueren, Edgar Knobloch, Leonardo Gordillo
Summary: An exactly solvable family of models describing the wrinkling of substrate-supported inextensible elastic rings under compression is identified. The resulting wrinkle profiles are shown to be related to the buckled states of an unsupported ring and are therefore universal. Closed analytical expressions for the resulting universal shapes are provided, including the one-to-one relations between the pressure and tension at which these emerge. The analytical predictions agree with numerical continuation results to within numerical accuracy, for a large range of parameter values, up to the point of self-contact.
PHYSICAL REVIEW LETTERS
(2022)
Article
Mathematics, Interdisciplinary Applications
M. Ahumada, A. Ledesma-Araujo, L. Gordillo, J. F. Marin
Summary: The COVID-19 crisis has raised concerns about the emergence of vaccine-escaping variants. In this article, a modified SIR model is proposed to capture the competition between two strain classes of the disease, including a deadlier and more contagious strain. The efficiency of vaccines and strain competition can lead to complex outcomes, and the critical vaccine efficiency values for disease eradication are determined. The model is validated using numerical studies with real data. This model can be used to quantitatively assess vaccination policies for competing and emerging strains in epidemics.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Mechanics
Palas Kumar Farsoiya, Quentin Magdelaine, Arnaud Antkowiak, Stephane Popinet, Luc Deike
Summary: This study performs direct numerical simulations to investigate the dissolution of a gas bubble in a surrounding liquid. The methods used are validated against analytical moving boundary problems and show good agreement. The results suggest that the mass transfer coefficient kL can be described by the classic Levich formula and that in turbulent flow, the coefficient is controlled by the smallest scales of the flow and is independent of the bubble size.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
C. R. Constante-Amores, L. Kahouadji, S. Shin, J. Chergui, D. Juric, J. R. Castrejon-Pita, O. K. Matar, A. A. Castrejon-Pita
Summary: We investigate the influence of insoluble surfactants on the impact of surfactant-free droplets onto surfactant-laden thin liquid films using a three-dimensional numerical simulation approach. Our results show that the presence of surfactants affects the late stages of the dynamics by delaying the end-pinching mechanisms, resulting in longer ligaments. We also demonstrate that the addition of surfactants leads to surface rigidification and retards the flow dynamics.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Multidisciplinary
Klebbert Andrade, Javiera Catalan, Juan F. Marin, Vicente Salinas, Gustavo Castillo, Leonardo Gordillo, Pablo Gutierrez
Summary: Certain spatial distributions of water inside partially filled containers can significantly reduce the bounce of the container. Rotation provides control and high efficiency in setting such distributions, leading to a substantial alteration in bounce. High-speed imaging captures the fluid dynamics processes and a model is developed to summarize the experimental findings.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Camila Sandivari, Jacob Egge, Belen Barraza, Leonardo Gordillo, Nicolas Mujica
Summary: We conducted an experimental study on a new type of dual drop-wave entity in a localized structure in a water Faraday-wave system. By analyzing the trajectories of the drops, we observed several regimes including periodic bouncing, period doubling, period tripling, a sawtooth state, and chaotic/erratic trajectories. We found that the most stable cases resulted from the synchronization between the drop self-oscillations and the soliton's sloshing motion. This synchronization ensures stability and longer lifetimes. We also analyzed the lifetime of the drops and found that they follow a Weibull distribution.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Physics, Multidisciplinary
Juan F. Marin, Rafael Riveros-Avila, Saliya Coulibaly, Majid Taki, Leonardo Gordillo, Monica A. Garcia-Nustes
Summary: Spatial nonuniformity significantly affects the motion of Faraday wave patterns, as evidenced by the zigzag and drift dynamics of their wave crests. A minimal theoretical model successfully characterizes the growth of localized patterns under nonuniform parametric driving. Numerical solutions of the governing equations match experimental findings and theoretical predictions. These results advance the understanding of pattern behavior induced by nonuniformity in generic nonlinear extended systems far from equilibrium.
COMMUNICATIONS PHYSICS
(2023)
Article
Chemistry, Physical
Ben D. Fudge, Radu Cimpeanu, Arnaud Antkowiak, J. Rafael Castrejon-Pita, Alfonso A. Castrejon-Pita
Summary: In this study, the impact dynamics of droplets onto liquid pools were investigated. It was found that the viscosity ratio between the pool and the droplet significantly influences the splashing threshold and the composition of the ejecta. Surprisingly, under certain conditions, no splashing was observed.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Mechanics
Thomas C. Sykes, Radu Cimpeanu, Ben D. Fudge, J. Rafael Castrejon-Pita, Alfonso A. Castrejon-Pita
Summary: When a fast droplet impacts a pool of the same fluid, the depth of the pool is revealed to be a critical factor in the formation of ejecta sheets. On deeper pools, the sheets fold inwards, while on shallower pools, they develop into outward-propagating lamellae. This transition is caused by a confinement effect of the pool base on the impact-induced pressure, which restricts flow into the ejecta sheet from the droplet.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
K. L. Meza-Alarcon, M. A. Quetzeri-Santiago, M. A. Neri-Flores, J. Antonio del Rio, J. R. Castrejon-Pita
Summary: In this study, the behavior and spreading dynamics of molten metallic alloy droplets were investigated. The impact behavior of five different solders was analyzed in terms of material and impact conditions. The results showed that the impact behavior could be well described by the splashing ratio and the maximum dynamic spreading contact angle. This study provides useful criteria for selecting the soldering injection speed and droplet size in industrial applications to prevent splashing during soldering or molten metal jetting.
