Article
Engineering, Chemical
Jihwan Yoon, Dongjae Kim, Seung-Hyun Lee, Dongjoon Kang, Jaewook Nam
Summary: Slot coatings are widely used for producing films with uniform thickness. Stable operating conditions are crucial for achieving desired thickness uniformity. In this study, a simplified visco-capillary model was proposed to estimate the operability window and solve inverse problems for producing thick films without a vacuum.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Water Resources
Faezeh Malekzadeh, Farzin Salmasi, John Abraham, Hadi Arvanaghi
Summary: This study investigates the effect of various parameters on the discharge coefficient of weirs through numerical simulation. The results show that the downstream face slope has little impact on the discharge coefficient, while the upstream slope, weir height, and crest length all affect the coefficient. Regression equations are developed for estimating the discharge coefficient based on numerical simulation results. The study also provides detailed information such as water level profiles and velocity profiles at different locations.
APPLIED WATER SCIENCE
(2022)
Article
Engineering, Civil
Wei Bowen, Lei Zhaoxing, Yuan Dongyang
Summary: This study proposes a new deformation monitoring model for concrete dams to analyze the operational state of dam structures and addresses the limitations of existing models in considering temperature effects. The proposed model effectively considers the hysteresis effect of temperature and reduces the uncertainty caused by temperature, providing a new method for dam deformation prediction.
ENGINEERING STRUCTURES
(2023)
Article
Chemistry, Applied
Jin Seok Park, Taehyung Yoo, Byoungjin Chun, Kwan-Young Lee, Hyun Wook Jung
Summary: The study investigated the operability windows and coating bead dynamics of a dual-layer slot coating process with non-Newtonian coating liquids using the viscocapillary model, CFD simulations, and experiments. Results showed that the viscocapillary model was able to accurately track the upstream meniscus position in the coating bead region. The onset of coating defects like leaking, bead break-up, and mid-gap invasion is strongly influenced by the rheological properties of Carreau-type coating liquids and the flow ratio between layers.
JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH
(2022)
Article
Physics, Applied
Liang Luo, Minghao Li, Zili Zhang, Li Tao
Summary: A new temporal centrality measure, upstream and downstream centrality (UD-centrality), has been proposed to assess the importance of nodes in social contact networks. Comparison results show that UD-centrality can more accurately rank the importance of nodes compared to traditional centrality measures.
MODERN PHYSICS LETTERS B
(2021)
Article
Engineering, Marine
Murali Kunasekaran, Madhan Kumar Paulraj, Shin Hyung Rhee, Nithya Venkatesan, Abdus Samad
Summary: In this study, the performance, flow field characteristics, and downstream turbine installation distance of a Marine Current Turbine (MCT) are compared using Unsteady Reynolds-Averaged Navier-Stokes (URANS) and SST-based improved delayed detached eddy simulation (SST-IDDES) models. Both models accurately predict the power and torque coefficients compared to experimental data. The URANS model shows less transient properties due to its isotropic character, while the SST-IDDES model predicts higher turbulence intensity due to its anisotropic nature. The results demonstrate that the SST-IDDES model is a reliable tool for analyzing the wake characteristics of marine current turbines.
JOURNAL OF MARINE SCIENCE AND TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
David C. Gisen, Cornelia Schuetz, Roman B. Weichert
Summary: By studying the behavior of brown trout in laboratory flume setups, we found that wall distance was the dominant stimulus for upstream orientation. This knowledge can be valuable for fishway studies and design.
Article
Astronomy & Astrophysics
G. Q. Wang, M. Volwerk, S. D. Xiao, M. Y. Wu, Y. Q. Chen, T. L. Zhang
Summary: The study reported on a new type of magnetic structure in the solar wind, which consists of pressure-balanced magnetic peaks with circular cross sections and an electron vortex. These structures exist upstream of the terrestrial bow shock and are approximately stationary in the ambient electron flow. The electron velocity shows a bipolar feature relative to the ambient flow in the cross section.
ASTROPHYSICAL JOURNAL
(2021)
Article
Engineering, Aerospace
Xiaobin Shen, Yundan Tan, Rendong Yu, Xiaochuan Liu, Guiping Lin, Zhiqiang Xu, Yuandong Guo
Summary: The study reveals that the collection efficiency and impingement characteristics of water droplets can be altered when bypassing aircraft components or influenced by air injection, with the Lagrangian method providing a more accurate simulation of these effects.
INTERNATIONAL JOURNAL OF AEROSPACE ENGINEERING
(2021)
Article
Development Studies
Lopamudra Chakraborti
Summary: The study provides empirical evidence that pollutant inputs from major point sources worsen downstream water quality, independent of upstream pollution levels and location-specific factors. Despite a small impact, the results are robust to distance traveled by pollutants and seasonal considerations.
JOURNAL OF ENVIRONMENTAL PLANNING AND MANAGEMENT
(2021)
Article
Environmental Sciences
Tim Haxton
Summary: The study estimated a theoretical threshold for facilitating upstream movement passed hydroelectric facilities for American eels in Ontario, Canada, while also finding that cumulative turbine-induced mortality during migration had a detrimental impact on the population, especially when encountering multiple hydroelectric facilities.
RIVER RESEARCH AND APPLICATIONS
(2022)
Article
Environmental Sciences
M-A Petre, K. R. Salk, H. M. Stapleton, P. L. Ferguson, G. Tait, D. R. Obenour, D. R. U. Knappe, D. P. Genereux
Summary: This study quantified PFAS concentrations and loads in Cape Fear River in North Carolina. The results showed that perfluoroalkyl acids dominated the upstream while fluoroethers associated with a manufacturing plant accounted for about 47% of the detected PFAS downstream. The average concentration of 43 PFAS near Wilmington was 143 ng/L, with 17-88% originating from the PFAS plant. Despite the cessation of PFAS process wastewater discharge, significant amounts of fluoroethers and legacy PFAS continue to enter the river, posing potential exposure risks to up to 1.5 million people in the watershed.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Marine
Sen Qu, Huilong Ren, Shengnan Liu, Shuzheng Sun, Muk Chen Ong
Summary: The numerical study of breaking waves interaction with two tandem cylinders using CFD software reveals the impact of transverse inclined angles and separation distances on breaking wave loads and free surface elevations. The VOF method is used to capture the air-water interface and the SST k - omega turbulence model is employed to solve the RANS equations.
SHIPS AND OFFSHORE STRUCTURES
(2022)
Article
Meteorology & Atmospheric Sciences
Jeremy D. Berman, Ryan D. Torn
Summary: Improving the evolution of Rossby waves can enhance the skill of medium-range weather forecasts. The predictability of downstream Rossby waves may be limited by forecast uncertainty related to diabatic processes such as latent heat release. Increasing the accuracy of initial conditions and simulating upstream diabatic processes can improve downstream forecast accuracy.
MONTHLY WEATHER REVIEW
(2022)
Article
Management
John Pastor Ansah, Keith Low Sheng Hng, Salman Ahmad, Cheryl Goh
Summary: This paper examines the impact of aging population, increasing prevalence of diabetes and hypertension on the number of CKD and ESRD patients needing dialysis, as well as the cost of dialysis. Results indicate a projected increase in the number of patients and policy experiments show that combined policies can lead to substantial cost savings.
SYSTEM DYNAMICS REVIEW
(2021)
Article
Chemistry, Physical
Sungwon Hong, Dongjae Kim, Yanghwan Jeong, Eunjoo Kim, Jae Chil Jung, Nakwon Choi, Jaewook Nam, Alex C. K. Yip, Jungkyu Choi
CHEMISTRY OF MATERIALS
(2018)
Article
Chemistry, Applied
Won-Gi Ahn, Si Hyung Lee, Jaewook Nam, See Jo Kim, Kwan-Young Lee, Hyun Wook Jung
JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH
(2018)
Article
Mechanics
Jaehyun Yoo, Jaewook Nam, Kyung Hyun Ahn
JOURNAL OF FLUID MECHANICS
(2019)
Article
Chemistry, Applied
Heechan Jung, Jaewook Nam
JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH
(2019)
Article
Materials Science, Multidisciplinary
Sang Hoon Sung, Do Hoon Kim, Sunhyung Kim, Min Hwan Jeong, Jaewook Nam, Kyung Hyun Ahn
JOURNAL OF MATERIALS SCIENCE
(2019)
Article
Materials Science, Multidisciplinary
Dongjae Kim, Sihyung Lee, Wooram Hong, Hyosug Lee, Seongho Jeon, Sungsoo Han, Jaewook Nam
MICROSCOPY AND MICROANALYSIS
(2019)
Article
Chemistry, Physical
Dongjae Kim, Jaewook Nam
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Mechanics
Hyungyeol Kwak, Jaewook Nam
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2020)
Article
Electrochemistry
Dongjae Kim, Jaewook Nam
Summary: Transparent conductive films made of metallic nanowires have complex microstructures composed of nanoscale conducting rods, which determine the electrical performance of the film. A network model was created using a multi-nodal representation and converted into an equivalent circuit using Laplacian eigenmap. Centrality concepts such as betweenness centrality, closeness centrality, and degree centrality were used to extract structural information and correlate with the conductivity of the network.
ELECTROCHIMICA ACTA
(2021)
Article
Mechanics
Hyungyeol Kwak, Jaewook Nam
Summary: This study presents two methods for obtaining the critical conditions for flow reversal onset in Couette-Poiseuille flows, one through solving algebraic equations and the other through local approximation. The methods showed reasonably low relative errors in most system parameter ranges, except in highly nonlinear flow curve cases.
JOURNAL OF RHEOLOGY
(2021)
Article
Chemistry, Physical
Sun Kyung Kim, Si Yoon Kim, Ju Young Lee, Jaewook Nam, Won Bo Lee, Seok Kim, Kyu Hyun
Summary: Research shows that ionic liquids (ILs) can enhance the ionic conductivity of solid polymer electrolytes (SPEs) but may have a detrimental effect on mechanical properties. Additionally, silica nanoparticles (SiNPs) do not significantly impact ionic conductivity in SPEs. The suspensions used for making SPEs exhibit shear thinning and yield stress behavior, depending on the concentrations of ILs and SiNPs.
JOURNAL OF POWER SOURCES
(2022)
Article
Engineering, Chemical
Hyungyeol Kwak, Jaewook Nam
Summary: This study investigates the influence of the coating gap on the maximum and minimum wet thicknesses in slot-die coating process, and establishes a simple flow model with analytical expressions. The results show that the minimum wet thickness increases linearly with the coating gap, while the maximum wet thickness exhibits a counterintuitive trend of decreasing with the increasing coating gap under a specific slot-die configuration.
Article
Materials Science, Multidisciplinary
Myungjae Lee, Hyunjoon Jung, Minho Lee, Hyungyeol Kwak, Jaewook Nam
Summary: Slot coating is commonly used in lithium-ion battery electrode manufacturing. However, using a battery slurry for coating experiments poses some challenges. In this study, a carboxymethyl cellulose (CMC) solution was proposed as a candidate for battery anode slurry for coating flows. The rheological properties of the slurry and model fluid were measured, and a computational analysis of the coating flow was conducted. The CMC solution was found to be a valuable candidate for experimental research on the coating flow of battery anode slurries.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Physics, Fluids & Plasmas
Nayeon Park, Jaewook Nam
Summary: This paper presents an in-depth analysis of pulsatile shear-thinning flows in two-dimensional channels by introducing the non-Newtonian Womersley number. It is found that the shape of the master curve is determined by the shear thinning degree, and the competition between viscous and pulsatile time scales can be appropriately described by this number.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Physics, Fluids & Plasmas
Junmo Lee, Jaewook Nam
Summary: This study investigates the percolation threshold of curved linear objects, represented as quadratic Bezier curves. By utilizing Monte Carlo simulations, critical number densities of the curves with varying curviness were calculated, along with the excluded area. Apparent conductivity exponents were computed, showing similarities with sticks in percolative systems, providing insights for analyzing the optoelectrical performance of metal nanowire films.
