Article
Multidisciplinary Sciences
Amit Nagarkar, Won-Kyu Lee, Daniel J. Preston, Markus P. Nemitz, Nan-Nan Deng, George M. Whitesides, L. Mahadevan
Summary: The experiment demonstrates how symmetry-breaking action in space-time can lead to locomotion of a thin circular sheet, allowing it to walk on land and swim in water. The shape asymmetry of the sheet in different modes of locomotion leads to asymmetric interactions with the environment, resulting in different modes of movement.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Engineering, Mechanical
Xianheng Guan, Likhitha Reddipalli, Dylan T. Butler, Qihan Liu, Sachin S. Velankar
Summary: This study experimentally demonstrates that a viscoelastic liquid exhibits a creasing instability similar to that of elastic materials, but with strain dependence on the rate of compression. The researchers developed a model to describe the creasing behavior of viscoelastic liquids and validated it through experiments.
EXTREME MECHANICS LETTERS
(2022)
Article
Chemistry, Physical
Sangmin Lim, Achyuta Yadunandan, M. Khalid Jawed
Summary: We present a bacteria-inspired centimeter-scale soft robotic hardware platform and a computational framework to simulate the multi-flagellated robot's motion under low Reynolds number. Comparison between experimental and simulation results confirms that the simulation tool accurately captures the essential physics of the problem.
Article
Mechanics
Yufei Wang, Zhiying Wang, Yan Du, Jingzhu Wang, Yiwei Wang, Chenguang Huang
Summary: This study investigates the dynamics of the surface-seal splash and develops an analytical model to understand its mechanics. The results indicate that the aerodynamic pressure plays a dominant role in the formation of the surface-seal splash.
Article
Multidisciplinary Sciences
Maojin Tian, Zhengyu Wu, Rongjing Zhang, Junhua Yuan
Summary: Bacterial motility and chemotaxis play a crucial role in environmental exploration and the spread of bacterial infections. This study revealed a swimming mode, called the wrap mode, which allows bacteria to efficiently explore their surroundings.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Polymer Science
Miwa Nakazawa, Masahiko Maeno, Mei Komoto, Yoichiro Nara
Summary: This study utilized quantitative and qualitative evaluations based on micro-tensile bond strength (μTBS) to demonstrate that the combined application of an adhesive system and a flowable resin composite for immediate dentin sealing (IDS) can enhance the bonding performance of CAD/CAM ceramic crown restorations. The group with the combined application showed the highest bond strength and durability, even under cyclic loading mimicking clinical mastication.
Article
Multidisciplinary Sciences
Dor Shohat, Daniel Hexner, Yoav Lahini
Summary: By crumpling a thin sheet, it exhibits unusual mechanical behaviors such as enhanced rigidity, emission of crackling noise, slow relaxations, and memory retention. These behaviors are attributed to the interplay between localized and interacting geometric instabilities in the sheet. Additionally, multiple memories can be encoded in the crumpled sheet after training.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Physical
Zoltan Karaszi, Marcell Mathe, Peter Salamon, Agnes Buka, Antal Jakli
Summary: Experimental observations were conducted on plano-convex lens-shaped nematic liquid crystal droplets under the simultaneous competing magnetic and electric fields. It was found that above a threshold electric field, the initially straight defect wall buckles to form a zig-zag shape.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Engineering, Civil
Christoph Adam, Ivan Paulmichl, Thomas Furtmueller
Summary: In this paper, stability-prone circular shallow arches composed of three symmetrically arranged flexibly bonded layers with fixed and hinged supports at both ends are examined. Analytical expressions for the limit points and bifurcation points are derived based on the differential equations of equilibrium and a series expansion of the governing kinematic variables. The accuracy of these analytical expressions is shown to be high compared to the results of complex numerical analyses.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Mechanics
Xuyang Chang, Matthieu Vitse, Stephane Roux
Summary: Analytical solutions for elastic buckling and post-buckling geometries are presented for a sample geometry that buckles into a complex 3D shape under tensile load. The solution assumes inextensibility and a small sample thickness. The initial geometry consists of two angular sectors that transform into cone sectors as the tensile load increases, while maintaining the sample extension along the tensile direction. This solution can be useful for validating numerical simulation tools or stereo-vision shape measurement procedures.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Engineering, Multidisciplinary
Rossana C. Jaca, Luis A. Godoy, Horacio D. Calabro, Susana N. Espinosa
Summary: This research focuses on the thermal buckling and post-buckling of vertical steel tanks under heat induced by a nearby burning tank. By adopting a two-layer solid flame model, heat transfer analysis, and finite element analysis, the study reveals the impact of temperature variations on the structural stability of tanks.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Physiology
Yasamin Seddighi, Hai-Chao Han
Summary: This study aimed to establish the theoretical foundation for noncircular blood vessel bent buckling and simulate the buckling behavior of arteries with elliptic and eccentric cross-sections using finite element analysis. The results showed that oval or eccentric cross-section increases the critical buckling pressure of arteries, and having both ovalness and eccentricity would further enhance the effect. The conclusion drawn was that variations of the cross-sectional shape affect the critical pressure of arteries, improving the understanding of the mechanical stability of arteries.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Shotaro Kikuchi, Seishiro Matsubara, So Nagashima, Dai Okumura
Summary: In this study, the diversity of bifurcations and deformations in periodic patterns on compressed films bonded to compliant substrates is investigated. It is found that different bifurcation modes lead to a family of herringbone deformation patterns with different dimensions, indicating a multiple and robust evolutionary process.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Engineering, Civil
Jeonghwa Lee, Young Jong Kang
Summary: This study investigates the local buckling behavior and strength of I-shape structural sections by considering flange-web interactions through three-dimensional finite element analysis. The study provides a more reasonable estimation of local buckling strength by considering the ratio of flange-web slenderness and height-to-width ratio, and presents design equations for flange local and web-bend buckling coefficients.
THIN-WALLED STRUCTURES
(2024)
Article
Chemistry, Physical
Yair Augusto Gutierrez Fosado, Fabio Landuzzi, Takahiro Sakaue
Summary: The relaxation dynamics of DNA circular plasmids undergoing a local twist perturbation is studied using analytical theory and Molecular Dynamics simulations. The twist-bend coupling in the DNA double helix due to groove asymmetry is clearly observed. Differences in diffusion coefficient values and dynamics are found in scenarios with and without this coupling, and can be explained by the existence of three distinctive time scales. Time scale separation allows the deduction of an effective diffusion equation with a diffusion coefficient influenced by twist-bend coupling.
Article
Energy & Fuels
Yuan Si Tian, Zi Qiang Yang, Sigurbur T. Thoroddsen, Ehab Elsaadawy
Summary: The separation of water droplets from water-in-crude-oil emulsions is crucial in the petroleum industry. A new experimental method involving optical-access flow, Near-Infrared laser illumination, and high-speed video imaging can help select the optimal demulsifier concentration by quantifying coalescence probability.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Ivan U. Vakarelski, Kenneth R. Langley, Fan Yang, Sigurdur T. Thoroddsen
Summary: This study examines the accuracy of numerical simulations in predicting the dynamics of thin liquid film drainage during the collision of bubbles or droplets. Experimental investigations of millimetric bubbles colliding with a flat glass interface in pure water were compared with numerical simulations using the open source Gerris flow solver. The simulation results showed excellent agreement with experimental observations in terms of the bounce trajectory and thin liquid film profile. The study highlights the potential of numerical simulations in resolving the complex processes of high velocity bubble and droplet collisions.
Article
Chemistry, Physical
Peter R. Birkin, Jack J. Youngs, Tadd T. Truscott, Silvana Martini
Summary: Optical sensing systems show potential for detecting bubbles or particles in oil, particularly in studying the effects of high intensity ultrasound on oils over extended time periods. The technique is based on an analytical basis and can track bubble populations even after the ultrasonic source has been terminated, making it useful for various research purposes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Adair Gallo, Nayara H. Musskopf, Xinlei Liu, Ziqiang Yang, Jeferson Petry, Peng Zhang, Sigurdur Thoroddsen, Hong Im, Himanshu Mishra
Summary: Recent research on the formation of hydrogen peroxide (H2O2) in water microdroplets has attracted significant attention. The presence of ozone (O-3) in the air has been found to have the most significant impact on H2O2 formation in these water microdroplets. Increased gas-liquid surface area facilitates the conversion of O-3 into H2O2.
Article
Mechanics
Akihito Kiyama, Rafsan Rabbi, Zhao Pan, Som Dutta, John S. Allen, Tadd T. Truscott
Summary: This study examines the interaction between a heated oil bath and water droplets, focusing on the explosion of millimeter-sized water droplets in heated oil. The findings describe the morphology of bubble dynamics inside a heated oil bath and its potential applications in cooking.
Article
Nanoscience & Nanotechnology
Yi Lu, Shibin Krishna, Che-Hao Liao, Ziqiang Yang, Mritunjay Kumar, Zhiyuan Liu, Xiao Tang, Na Xiao, Mohamed Ben Hassine, Sigurdur T. Thoroddsen, Xiaohang Li
Summary: This article introduces a method for transferring Ga2O3 thin film to arbitrary flexible and adhesive tape, enabling vertical and flexible configurations of electronic devices. Vertical photodetectors fabricated using this method demonstrate good optoelectronic performance.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Ivan U. Vakarelski, Farrukh Kamoliddinov, Sigurdur T. Thoroddsen
Summary: This study investigates the interaction between millimeter-sized bubbles and the seawater-air interface in seawater samples collected from the Red Sea coastal area. It demonstrates that high concentrations of electrolytes and organics in seawater do not affect the mobility of the bubble interfaces during free-rise and bouncing.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Materials Science, Multidisciplinary
M. Jimenez-Valdez, E. Tomay, J. O. Marston, F. Pacheco-Vazquez
Summary: This study investigated the formation of doublet craters, which are created by binary projectiles impacting simultaneously at low speed on a sand bed. The morphology of the craters varied depending on the initial separation between the projectiles, including two well-defined craters, overlapping craters, or a single larger circular crater when the separation was negligible. The delay between impacts caused asymmetry in the ridge and ejecta curtains, with the delayed projectile penetrating deeper due to bed fluidization and material displacement from the first impact.
Article
Engineering, Chemical
Christopher Wagstaff, Sreenivasa Rao Gubba, Tadd Truscott, Khalid Algashgari, William L. Roberts
Summary: Arrays of vertical parallel wires ('wetted wires') can be an effective alternative to traditional industrial columns, but more research is needed to optimize their performance and compete against packed columns. This study investigates the maximum wire density for wetted-wire columns using the minimum pitch, and the results show that the pitch can be much smaller than previously recommended. An analytical model is used to compare the pressure drop characteristics of wetted-wire columns with existing packings, revealing that wetted-wire columns have significantly lower pressure drops. However, the packing factors used for packed columns do not adequately describe the fluid dynamics of wetted-wire columns.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Mechanics
Yuan Si Tian, Zi Qiang Yang, Sigurdur T. Thoroddsen
Summary: Fast microjets can be produced when drop-impact craters rebound or when a bubble bursts, and they play a crucial role in climate and olfactory senses as a source of aerosols. The most unique and fastest jets are generated when a small dimple forms at the crater bottom and rebounds without pinching off a small bubble. High-resolution numerical simulations reveal a new focusing mechanism that explains the extreme sensitivity to initial conditions observed in experiments of this phenomenon.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Jesse Belden, Nathan B. B. Speirs, Aren M. M. Hellum, Matthew Jones, Anthony J. J. Paolero, Tadd T. T. Truscott
Summary: It has been discovered that the water entry of a body with a recessed, cupped nose can suppress the splash and air cavity typically observed. However, the interplay between the captive gas in the cup, the cavity, and the splash has not been thoroughly explored. In this study, the cavity and splash dynamics of cups during vertical water entry are investigated and a variety of regimes are identified.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Esraa Fakeih, Andres A. Aguirre-Pablo, Sigurdur T. Thoroddsen, Khaled N. Salama
Summary: This study investigates the design and fabrication of porous microneedles (MNs) and finds that injection through porous MNs results in a broader diffusion spread compared to hollow MNs. Three different designs of porous MNs with a constant pore size and controlled pore locations are fabricated using two-photon polymerization (2PP), and factors such as diffusion spread, mixing capabilities, and mechanical resilience are examined. The results show that porous MNs can cover 16 times the injection area of hollow MNs and demonstrate good mixing capabilities and mechanical strength.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Mechanics
Farrukh Kamoliddinov, Ivan U. Vakarelski, Sigurdur T. Thoroddsen, Tadd T. Truscott
Summary: In this experimental study, we investigated the hydrodynamics of a buoyant sphere accelerated along an air-water interface. The sphere displayed different behaviors depending on its speed, from floating on the surface to oscillating underwater and generating air cavities. These underwater air cavities were attached to the sphere surface near the laminar flow separation point. By changing the pulling angle and counterweight-induced velocity, we explored the effects on the hydrodynamics. Additionally, we analyzed the complex fluid-solid interactions and the influence of the air cavity on drag and lift coefficients and overall sphere hydrodynamics, particularly above the critical Froude number of 1.2.
Article
Chemistry, Physical
Zi Qiang Yang, Peng Zhang, Meng Shi, Ali Al Julaih, Himanshu Mishra, Enzo Di Fabrizio, Sigurdur T. Thoroddsen
Summary: Polymer filaments have important applications in biology, tissue engineering, and molecular machines. Researchers have developed a simple method to deposit stretched polymer fibers between micro-pillars, allowing for characterization of filament-forming configurations and their properties.
Article
Chemistry, Physical
Peter R. Birkin, Jack J. Youngs, Tadd T. Truscott, Silvana Martini
Summary: This article discusses the mechanisms of enhancing lipid crystallization through the application of ultrasound and explores factors affecting the ultrasound effect, such as bubble cluster types, pressure shocks, and mechanical agitation. The research findings suggest that large bubble populations and mechanical effects on pre-existing crystals play important roles in the crystallization rate.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
