Article
Chemistry, Analytical
Nasim Hajari, Carlos Lastre-Dominguez, Chester Ho, Oscar Ibarra-Manzano, Irene Cheng
Summary: Pressure injury is a major concern for patients confined to wheelchairs or beds, and can be prevented by adjusting patient poses and monitoring in-bed pressure. Current clinical monitoring methods are limited, hence a more efficient pressure signal analysis pipeline is needed for better prevention and treatment of PI.
Article
Chemistry, Analytical
Mohaddeseh Aref, Elias Ranjbari, Juan Jose Garcia-Guzman, Keke Hu, Alicia Lork, Gaston A. Crespo, Andrew G. Ewing, Maria Cuartero
Summary: The pH nanosensor developed for single intracellular measurements showed a Nernstian response with good repeatability, fast response time, and a linear range of response. Cell-based experiments confirmed the reliability of the sensor in providing unbiased pH measurements and it was successfully applied in tracing pH gradients and monitoring variations in intracellular pH in response to pharmaceuticals, demonstrating its high potential for investigating pathological states related to cell pH misregulation.
ANALYTICAL CHEMISTRY
(2021)
Article
Cell Biology
Kiet A. Tran, Abigail Baldwin-Leclair, Brandon J. DeOre, Morgan Antisell, Peter A. Galie
Summary: This study investigates the effects of biophysical variables on angiogenic sprouting of cerebral endothelial cells using a three-dimensional brain microvascular model. The results show that fluid shear stress and vessel geometry both attenuate sprouting. Computational modeling and oxygen consumption assays suggest that sprouting is correlated with reduced oxygen concentration, which is influenced by both shear stress and vessel geometry. Increasing cell density and lowering local oxygen levels promote sprouting. Spatial oxygen gradients, rather than overall oxygen concentration, are found to be the driving force of angiogenesis in the brain.
JOURNAL OF CELLULAR PHYSIOLOGY
(2022)
Article
Biology
David J. Daegling, Henna D. Bhramdat, Viviana Toro-Ibacache
Summary: The study explores the mechanical variables responsible for osteogenic activity and the coordination of periosteal and endosteal expansion. Developmental simulations indicate that different growth algorithms result in varied mechanical competence and material economy in bone growth.
JOURNAL OF THEORETICAL BIOLOGY
(2021)
Article
Multidisciplinary Sciences
Nihad E. Daidzic
Summary: This study presents a general unified solution for the plane Couette-Poiseuille-Stokes-Womersley flow in the presence of oscillatory pressure gradients and periodic synchronous vibrating boundaries. The exact analytical solution is obtained using the eigenfunction expansion method and Fourier expansion. The results are verified and tested using a computational fluid dynamics method. The study shows that the combined effects of non-harmonic wall movements and oscillatory pressure gradients can result in rich and interesting flow patterns.
Article
Energy & Fuels
Chunguang Zhou, Christer Rosen, Klas Engvall
Summary: This study investigated the fragmentation behaviors of dolomite under pressurized gasification conditions and proposed measures to mitigate dolomite fragmentation. The results showed that high operating pressure and high P-H2O are beneficial for fragmentation mitigation, and it is recommended to pressurize to the operating pressure before reaching the initial fragmentation temperature of dolomite during the reactor heating-up stage.
Article
Environmental Sciences
F. Maager, B. Hohermuth, R. M. Boes, V. Weitbrecht
Summary: A step-pool bed morphology often occurs in steep mountain streams. The increase in bed stability caused by macrorough sidewalls is mainly attributed to the grain-sidewall interlocking. The hydraulic effects and granular effects have different influences on step formation and stability in various channel conditions.
WATER RESOURCES RESEARCH
(2023)
Article
Engineering, Geological
Kendra White, Yuntong She, Wenming Zhang
Summary: This study compared different methods for estimating bed shear stress and found that the turbulent kinetic energy method with newly calibrated proportionality constants was the most accurate in representing the local bed shear stress on geobags. The Reynolds stress method was relatively unaffected by changes to the geobags' shape and measurement locations, but inadequately represented the local bed shear stress. The Patel method and universal law of the wall method failed to accurately represent bed shear stress in rough bed cases.
GEOTEXTILES AND GEOMEMBRANES
(2022)
Article
Engineering, Civil
Xiang Wang, Carlo Gualtieri, Wenxin Huai
Summary: The impact of aquatic vegetation on weak bed-load transport rates in riverbeds was investigated through laboratory experiments. It was observed that the transport rate increased with an increase in energy slope and a decrease in vegetation density. The traditional method of calculating bed shear stress was unable to predict the measured transport rate, but a new method considering grain shear stress provided a reasonable prediction. The proposed models were found to be more accurate than existing literature models, improving understanding of bed-load transport in vegetated flows.
JOURNAL OF HYDROLOGY
(2023)
Article
Engineering, Civil
Jie Zhang, Magnus Larson
Summary: This technical note presents methods for direct computation of bed roughness due to sediment transport, resulting in approximate nondimensional expressions for accurate solutions in terms of polynomials determined by least-square fits. The high accuracy of these polynomials may significantly reduce calculation times in numerical models for morphological change.
JOURNAL OF HYDRAULIC ENGINEERING
(2021)
Article
Engineering, Manufacturing
Ben Amir, Eytan Kochavi, Shimon Gruntman, Yuval Gale, Shmuel Samuha, Oren Sadot
Summary: This study experimentally investigated the shear behavior of LPBF AlSi10Mg and found that shear strength considerably increased with an increase in shear load rate. In the quasi-static regime, shear strength was practically independent of the product build direction, while under dynamic shear conditions, horizontally built samples exhibited a shear strength approximately 10% lower than vertically built samples.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Civil
Jiajia Pan, Hung Tao Shen, Nian-Sheng Cheng
Summary: Experimental studies have proposed various empirical equations for mean bed and wall shear stresses in smooth rectangular open channels. By modifying the gravity force parameter used for dimensionalizing shear stresses to include width and wetted-perimeter, new dimensionless equations have been derived that accurately predict shear stresses and the wall/bed shear force ratio. These equations also provide new relationships for bed and wall friction factors.
JOURNAL OF HYDRAULIC RESEARCH
(2021)
Article
Environmental Sciences
Reza Shahmohammadi, Hossein Afzalimehr, Jueyi Sui
Summary: This experimental study aimed to estimate bed shear stress in shallow water flows by evaluating fluid dynamics characteristics under various conditions. The results showed that certain values were proportional to the shear Reynolds number.
Article
Chemistry, Physical
Mohamed Amine Benmebarek, Majid Movahedi Rad
Summary: This paper investigates the micro and macro behaviors of coarse sand during a geotechnical test using a direct shear box. A 3D discrete element method model is used to explore the ability of the rolling resistance linear contact model to reproduce the test considering real-size particles. The study focuses on the interaction of contact model parameters and particle size on shear stress and volume change.
Article
Engineering, Mechanical
Beibei Xu, Shaotong Zhang, Peter Nielsen, Davide Wuethrich
Summary: Shear plates have been used to measure bed shear stresses near the tip and even at distances less than one plate length from the tip. In order to resolve rapid stress variation, the shear plate was calibrated with respect to its step response and statically. It was found that the bed shear stress increases almost linearly with time, whereas water level rises to a quasi-steady level under the present experimental conditions, indicating that the simple assumption of tau bed=tau bed roughnessdepth is not supported.
EXPERIMENTS IN FLUIDS
(2021)
Article
Mechanics
Zhengtong Yang, Philip L-F Liu
Summary: The present study extends the depth-integrated wave-current models to investigate currents with an arbitrary vertical profile in the water column. The models decompose the horizontal velocities into two components, and the resulting models are validated and applied to wave-current interactions in one-dimensional and two-dimensional spaces. The vertical and horizontal shear of the current have significant effects on modifying various wave properties, and the resulting models capture these effects well.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Meteorology & Atmospheric Sciences
James T. Kirby, Stephan T. Grilli, Juan Horrillo, Philip L-F Liu, Dmitry Nicolsky, Stephane Abadie, Behzad Ataie-Ashtiani, Manuel J. Castro, Lucie Clous, Cipriano Escalante, Isaac Fine, Jose Manuel Gonzalez-Vida, Finn Lovholt, Patrick Lynett, Gangfeng Ma, Jorge Macias, Sergio Ortega, Fengyan Shi, Saeedeh Yavari-Ramshe, Cheng Zhang
Summary: The Mapping and Modeling Subcommittee of the US National Tsunami Hazard Mitigation Program held a workshop in January 2017 to evaluate numerical models for simulating tsunamis caused by submarine or subaerial landslides. Benchmark tests were conducted, showing the importance of including frequency dispersion in model formulations to obtain accurate results.
Article
Multidisciplinary Sciences
Kuifeng Zhao, Philip L-F Liu
Summary: Using MATLAB(R) Symbolic Toolbox and perturbation method, a new set of Stokes wave solutions, including free surface profile, velocity potential and wave celerity, are derived. Comparisons with existing solutions up to the fifth order reveal differences starting at the third order, and the causes for these differences are identified. The characteristic differences in high order solutions of Stokes waves are highlighted in the figures.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Acoustics
Markus Bruehl, Peter J. Prins, Sebastian Ujvary, Ignacio Barranco, Sander Wahls, Philip L. -F. Liu
Summary: In this paper, the propagation of bores over a long distance is studied using experimental data and numerical simulations. The periodic KdV-NFT is found to reliably predict the number and amplitudes of far-field solitons, even though the propagation is only approximated by the KdV. In contrast, the conventional linear FT is unable to reveal the hidden solitons in the bore. The study also investigates the predictive capabilities of the time and space versions of KdV.
Article
Physics, Fluids & Plasmas
Kunlin Ma, Nimish Pujara, Jean-Luc Thiffeault
Summary: This study investigates the vertical transport of microswimmers in waves and finds that the shape and swimming speed of microswimmers have an impact on their vertical transport. The trajectories of microswimmers are bounded by critical planes in the position-orientation phase space, and the fraction of microswimmers reaching the surface varies with shape and swimming speed.
PHYSICAL REVIEW FLUIDS
(2022)
Letter
Limnology
Devin N. Castendyk, Hilary A. Dugan, Hugh A. Gallagher, Nimish Pujara, Peter T. Doran, John C. Priscu, W. Berry Lyons
Summary: This study reveals the presence of wind-driven barotropic seiches in Lake Hoare, East Antarctica, mainly occurring during high wind events in winter and with increasing period during summer when fast ice melts along the shoreline.
LIMNOLOGY AND OCEANOGRAPHY LETTERS
(2022)
Article
Environmental Sciences
Benjamin Davidson, Kallyn Batista, Sabeel Samrah, Lorena M. Rios Mendoza, Nimish Pujara
Summary: This study examines microplastic pollution in sediments from three beaches in western Lake Superior and finds that the contamination is widespread. Polyester fibers are the main component of microplastics, and the degree of pollution varies significantly among beaches. The distance from microplastic sources to the lake does not appear to be a determining factor for the variation. The study also reveals that the location and depth of sediments do not significantly affect microplastic concentrations.
JOURNAL OF GREAT LAKES RESEARCH
(2022)
Article
Economics
Jiqian Wang, Feng Ma, Elie Bouri, Yangli Guo
Summary: This study explores the role of macroeconomic and technical indicators in forecasting Bitcoin volatility and finds that macroeconomic indicators have stronger predictive power overall, while technical indicators are more effective during periods of low volatility.
JOURNAL OF FORECASTING
(2023)
Article
Mechanics
Ignacio Barranco, Philip L. -F. Liu
Summary: This study includes a large region with specific geographical characteristics and covers almost a quarter of registered patients in Slovenia, which increases the generalizability of the results. One limitation is that the presence of chronic diseases was self-reported, which may introduce bias. Another limitation is the discrepancy between self-reported obesity and obesity calculated based on BMI. The study was partly supported by the Norwegian government and the Slovenian public health research agency.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Civil
Xiaochun Tang, Pengzhi Lin, Yu-Hsi Lin, Yun Jiang, Philip L. -F. Liu
Summary: A series of laboratory experiments were conducted to study the characteristics of turbulence kinetic energy (TKE) inside suspended vegetation domain when waves interacted with it. The vegetation was modeled using vertical cylinders in three different configurations, and the velocities inside and outside the vegetation domain were measured. The drag force coefficients were calculated, and a negative current was found near the bottom of the vegetation domain. The time-averaged and phase-averaged TKE, as well as the variations of measured force, were analyzed. A new model was proposed and validated using experimental data.
JOURNAL OF WATERWAY PORT COASTAL AND OCEAN ENGINEERING
(2023)
Article
Engineering, Civil
Peter H. -Y. Lo, Philip L. -F. Liu
Summary: A simplified approach was proposed to efficiently simulate tsunamis generated by submarine slumps. The landslide tsunami generation process was parameterized by 11 input parameters, which can be used as initial conditions in numerical tsunami propagation models. The results of the simulation were compared with field measurements and tuning-based wave profiles, and sensitivity tests revealed the uncertain nature of landslide tsunamis.
COASTAL ENGINEERING
(2023)
Article
Engineering, Marine
Yu Hsiao, Shih-Chun Hsiao, Philip Li-Fan Liu
Summary: In this study, the interaction between a solitary wave and a bottom-mounted, submerged elastic plate was numerically investigated. The effects of plate height, plate thickness, and the Young's modulus of plate material on the hydrodynamics were studied using a fluid structure interaction solver, a turbulence closure model, and a volume of fluid approach. The plate displacement was calculated using the Euler-Bernoulli beam theory. The wave nonlinearity and plate material properties were found to have significant effects on wave reflection, transmission, and dissipation.
Article
Mechanics
P. l. -F. Liu, P. Higuera, P. H. -Y. Lo
Summary: This paper investigates the generation mechanism of tsunamis caused by a moving atmospheric pressure disturbance. By analyzing the complex wave field generated by the scattering of locked and free waves due to bathymetric variations and coastlines, analytical solutions are obtained using the Fourier transform method. The study reveals the complexity of wave scattering processes and the significant differences between locked and free waves.
Editorial Material
Mechanics
Hua Liu, Philip L-F. Liu, Frederic Dias
Article
Physics, Fluids & Plasmas
Nimish Pujara, Jean-Luc Thiffeault
Summary: This study models the motion of particles such as microplastics and phytoplankton in a wavy environment and examines how the particle shape and buoyancy affect the particle orientation, drift, and dispersion driven by waves. The findings show that particles have a wave-induced preferential orientation, reduced settling velocity, and increased horizontal dispersion under wave action.
PHYSICAL REVIEW FLUIDS
(2023)