Article
Agricultural Engineering
Miroslav Rebej, Tomas Jurena, Jiri Vondal, David Fuente Herraiz, Jan Cerveny, Zdenek Jegla
Summary: This paper presents the use of PIV technique to measure velocity fields in a stirred photobioreactor and validate a CFD model. The study includes grid independence analysis, velocity profiles, and shear stresses for different operating conditions. The results show good correlation between the numerical model and experimental data, but uncertainties exist in PIV measurements for bubbly flows.
BIOSYSTEMS ENGINEERING
(2023)
Article
Biology
Romana Perinajova, Joe F. Juffermans, Jos J. M. Westenberg, Roel L. F. van der Palen, Pieter J. van den Boogaard, Hildo J. Lamb, Sasa Kenjeres
Summary: The study reveals that aortic aneurysm is associated with aberrant blood flow and wall shear stress, which can be studied through MRI and CFD. Attention should be paid to the effect of MRI segmentation variations on wall shear stress in patient-specific simulations. Comparing mean and maximal values of WSS in different segments of the thoracic aorta shows good to excellent correlation for rescan, while voxel-to-voxel comparison yields poorer results.
COMPUTERS IN BIOLOGY AND MEDICINE
(2021)
Article
Chemistry, Multidisciplinary
Hawa Ringkai, Khairul Fikri Tamrin, Nadeem Ahmed Sheikh, Shahrol Mohamaddan
Summary: This study investigates the behaviors of water-in-oil droplets in an offset T-junction microchannel with different radii using micro-PIV software. The results show that increasing the radius of the microchannel leads to an increase in cross-sectional area and a decrease in the velocity of the water phase, with experimental velocities of the water droplets closely matching theoretical values.
APPLIED SCIENCES-BASEL
(2021)
Article
Biochemical Research Methods
Mathias Busek, Aleksandra Aizenshtadt, Timo Koch, Anna Frank, Ludivine Delon, Mikel Amirola Martinez, Alexey Golovin, Clotilde Dumas, Justyna Stokowiec, Stefan Gruenzner, Espen Melum, Stefan Krauss
Summary: We developed a pump-less directional flow recirculating organ-on-a-chip platform that creates controlled unidirectional gravity-driven flow. The platform features two organoid compartments supported by independent perfusion channels, separated by a hydrogel barrier. We demonstrated the suitability of the platform for functional culture of endothelial cells and the viability of human stem-cell derived liver organoids, as well as the circulation of immune cells in the microfluidic channels.
Article
Chemistry, Multidisciplinary
Patrick Fillingham, Arjun Viswanathan, Igor Novosselov
Summary: This study investigates the wall stress resulting from inclined under-expanded planar jets using computational fluid dynamics and establishes an empirical relationship between wall shear stress and jet parameters. The findings can be applied to design and assess the performance of practical systems.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Julian Giehler, Leo Chamard, Carola Ebert, Julien Weiss, Alain Giani, Philippe Combette
Summary: The most significant design parameters of MEMS calorimetric wall shear stress sensors are determined through experimental and numerical investigations. The inter-beam distance and cavity width are found to be the most important parameters, while the cavity height has minor significance.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Review
Cardiac & Cardiovascular Systems
Manli Zhou, Yunfeng Yu, Ruiyi Chen, Xingci Liu, Yilei Hu, Zhiyan Ma, Lingwei Gao, Weixiong Jian, Liping Wang
Summary: Atherosclerosis (AS) is a major form of cardiovascular disease with high morbidity and mortality rates globally. The development of AS is strongly influenced by hemodynamic factors, particularly wall shear stress (WSS), which can either promote or prevent AS progression. Computational fluid dynamics (CFD) modeling is used to study the characteristics of WSS, providing insights into the early lesions and vulnerable phenotypes of AS. The use of WSS as an effective parameter for early diagnosis of AS is becoming a reality and should be actively promoted in clinical practice.
FRONTIERS IN CARDIOVASCULAR MEDICINE
(2023)
Article
Thermodynamics
Muhammad Zia Ullah Khan, Bilal Akbar, Ramisha Sajjad, Umair Ahmed Rajput, Sanaullah Mastoi, Emad Uddin, Azhar Hussain, Md Yamin Younis, Fausto Pedro Garcia Marquez, Naveed Akram
Summary: This study investigates heat transfer enhancement in a straight rectangular channel with and without disturbances in the form of dimple protrusions. The results show that circular dimple-protrusion channels are effective for high Reynolds numbers, while through dimple protrusion channels are efficient for intermediate Reynolds numbers. Additionally, the addition of copper oxide nanoparticles improves heat transfer performance in the channels.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Engineering, Mechanical
Qianhui Li, Evangelos Stavropoulos-Vasilakis, Phoevos Koukouvinis, Manolis Gavaises, Christoph H. Bruecker
Summary: This study developed a method for calibrating wall-shear stress sensors in complex geometries, assisted by numerical simulation data. By calibrating and testing in the aorta model, it demonstrated the different impacts of two different heart valves on wall-shear stress in the aortic arch.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Biotechnology & Applied Microbiology
M. Yousuf Salmasi, Selene Pirola, Sumesh Sasidharan, Serena M. Fisichella, Alberto Redaelli, Omar A. Jarral, Declan P. O'Regan, Aung Ye Oo, James E. Moore, Xiao Yun Xu, Thanos Athanasiou
Summary: The study found that elevated values of WSS in ATAA patients were associated with aortic wall degradation, indicating a potential relationship between WSS and the progression of ATAA disease. Further research may help in identifying threshold values to predict acute aortic events.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Engineering, Chemical
Krystian Jedrzejczak, Arkadiusz Antonowicz, Lukasz Makowski, Wojciech Orciuch, Krzysztof Wojtas, Michal Kozlowski
Summary: We aimed to verify the relationship between blood vessel shape and hemolysis risk by using a blood rheological model that considers physiological processes related to blood flow. The model predicted red blood cell concentration and agglomerate size, important factors affecting blood rheology and hemolysis. We compared computational fluid dynamics simulation results with experimental measurements to establish a correlation function between vessel shape, flow rate, and maximum shear stress, which governs hemolysis. This study successfully applied chemical engineering methodology to analyze biological systems and has the potential to be implemented in medical practice for quickly assessing hemolysis risk.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Engineering, Chemical
Yi Fan, Jianping Li, Qi Wei, Ziyou Xiong, Yujie Ji, Hongpeng Ma, Bing Liu, Yuan Huang, Wenjie Lv, Hualin Wang
Summary: Global separation energy consumption accounts for a significant portion of total energy consumption, and the development of non-thermal separation methods offers a new direction for global energy development. However, the accuracy of cyclone separation is limited, and no significant breakthroughs have been achieved in this field in the past century. This study proposes a slice test particle image velocimetry (S-PIV) methodology to explore the turbulent flow characteristics of different structures and flow rates in micro-hydrocyclones. The results demonstrate the effectiveness of S-PIV as a replacement for expensive and cumbersome particle analyzers, and establish the relationship between turbulent flow parameters and particle motion.
Article
Energy & Fuels
Jan Stasiek, Adam Stasiek, Marek Szkodo
Summary: The main goal of the research presented in this paper was to experimentally and numerically analyze heat enhancement and aerodynamic phenomena during airflow in a channel equipped with flow turbulators in the form of properly configured ribs. The use of ribs intensifies heat transfer while increasing flow resistance and energy costs. Optical tools such as Liquid Crystal Techniques, Particle Image Velocimetry, and Digital Image Processing are utilized to measure temperature, velocity, friction factor, and heat transfer coefficient.
Article
Thermodynamics
Fabio Berni, Giuseppe Cicalese, Massimo Borghi, Stefano Fontanesi
Summary: Convective heat transfer plays a crucial role in industrial processes, and the accurate estimation of heat fluxes is essential for design. 3D-CFD simulations are widely used due to the limitations of experimental methods in many applications. The combination of RANS turbulence modeling and high-Reynolds wall treatment is common for efficiency and time-saving in industrial practices. The presence of low y(+) values in in-cylinder simulations can lead to overestimation of wall shear stress and heat transfer, necessitating modified formulations for accurate predictions.
APPLIED THERMAL ENGINEERING
(2021)
Review
Thermodynamics
Khadije El Kadi, Fadi Alnaimat, S. A. Sherif
Summary: The paper provides a comprehensive review of condensation studies in microchannels conducted in the last two decades, including experimental investigations, theoretical predictive models, and computational predictions. It presents a wide range of operating conditions, channel geometries, heat transfer fluids, research methods, and advancements in condensation heat transfer in mini and microchannels.
APPLIED THERMAL ENGINEERING
(2021)
Article
Engineering, Chemical
Petr Kluson, Petr Stavarek, Vera Penkavova, Hana Vychoclilova, Stanislav Hejda, Magdalena Bendova, Marek Dosek
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2020)
Article
Chemistry, Analytical
Georgia Kontaxi, Yorgos G. Stergiou, Aikaterini A. Mouza
Summary: This study compares the characteristics of bubbles formed in non-Newtonian and Newtonian fluids, finding that the final diameter of the bubbles is influenced by the gas flow rate and liquid phase viscosity. Simulation results indicate that high shear rates around bubbles in non-Newtonian fluids lead to the viscosity approaching its asymptotic value.
Article
Materials Science, Multidisciplinary
Vera Penkavova, Lukas Kulaviak, Marek C. Ruzicka, Miroslav Puncochar
Summary: Experimental study on random layers of dry coarse anisometric grains of eight different materials was conducted, evaluating static and dynamic parameters of compression and shear tests. The relationship between compaction and flow properties was determined based on compression and shear models parameters, with results compared to published data on common powders.
Article
Engineering, Chemical
Nirmal Parmar, Magdalena Bendova, Zdenek Wagner, Vera Penkavova, Ilias Douihri, Johan Jacquemin
Summary: Ionanofluids (INFs), ionic liquids (ILs) containing dispersed nanoparticles, exhibit fascinating thermophysical properties. This study reports the heat capacity, viscosity, melting temperature, and electrical conductivity of INFs based on 1-ethyl- 3-methylimidazolium bis(trifluoromethylsulfonyl)imide and utilizes mathematical diagnostics for uncertainty estimation and robust linear regression for curve fitting.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Geochemistry & Geophysics
Maria Zednikova, Jakub Crha, Lucie Vobecka, Pavlina Basarova, Jiri Vejrazka, Jaroslav Tihon
Summary: This study investigates the basic processes occurring in three-phase systems where small bubbles interact with large particles, specifically focusing on the effects of two specific surfactants. Results show that even small concentrations of surfactants significantly suppress both the bubble shape oscillations and the bubble bouncing on the solid surface. Predictions for the restitution coefficient are successfully proposed based on the balance of various forces in the system.
Article
Engineering, Chemical
Kingsley Ezeji, Jaroslav Tihon
Summary: The study investigates the wall shear rate induced by large air bubbles rising in inclined rectangular channels using a two-strip electrodiffusion probe. Synchronized high-speed camera recordings provide additional information on bubble shapes and movements, while measurements are conducted over a wide range of operation parameters and inclination angles. The study aims to elucidate the influence of individual operating parameters on the bubble induced wall shear rate profile.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Vera Penkavova, Anna Spalova, Jan Tomas, Jaroslav Tihon
Summary: Polyacrylamide (PAAm) hydrogels can be tuned by adjusting the water content in the reaction mixture, and they exhibit reversible swelling/shrinking behavior that can be used for remote control of hydrogel properties.
POLYMER ENGINEERING AND SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Vera Penkavova, Anna Spalova, Jaroslav Tihon
Summary: Polyacrylamide (PAAm) hydrogel-based nanocomposites were prepared with the addition of graphene, kaolin, or laponite as possible adsorbents for organic dyes. The morphology of the hydrogels was controlled by varying water content, and the composition of the nanocomposites was modified by changing the type and amount of additive. The physicomechanical properties of the nanocomposites were influenced by hydrogel morphology and additives, with higher water content leading to less rigid nanocomposites, and the additives affecting rigidity differently. The adsorption properties of the nanocomposites varied depending on the additive, with laponite showing the most significant increase in adsorption capacity.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Thermodynamics
Vaclav Harrandt, David Kramolis, Florian Huchet, Jaroslav Tihon, Jaromir Havlica
Summary: This article derives the fundamental theory for mass transport on the active surface of a two-strip mass transfer probe for any direction of fluid flow. The existence of such a general theory is crucial for the application of the electrodiffusion method using a two-strip probe. Analytical formulas for the average mass transfer coefficients, presented in dimensionless forms for both segments, are derived considering different possible sizes of the probe segments. The correctness of the derived analytical expressions is verified through numerical solution of the convection-diffusion transport equation. A methodology for possible experimental data treatment is proposed based on the evaluation of two current signals collected from the segments of a two-strip probe. From the derived equations, the magnitude and direction of the wall shear rate vector for both frontal and reverse flow regimes can be determined. An optimal probe configuration is found with respect to the sensitivity of the flow direction measurement through the analysis of the current ratio predictions for different probe geometries.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Geochemistry & Geophysics
P. Broz, O. Kryza, V. Patocka, V. Penkavova, S. J. Conway, A. Mazzini, E. Hauber, M. E. Sylvest, M. R. Patel
Summary: Subtle mounds have been discovered on Mars and are believed to be related to the movement of subsurface sediment. Experiments have shown that the low atmospheric pressure on Mars can cause water instability in mud, leading to an increase in volume. This suggests that mud flows on Mars could behave differently to those on Earth, resulting in different formations.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Physics, Fluids & Plasmas
Yorgos G. Stergiou, Athanasios G. Kanaris, Aikaterini A. Mouza, Spiros V. Paras
Article
Physics, Fluids & Plasmas
Angeliki T. Koupa, Yorgos G. Stergiou, Aikaterini A. Mouza
Correction
Physics, Fluids & Plasmas
Aikaterini A. Mouza, Olga D. Skordia, Ioannis D. Tzouganatos, Spiros V. Paras
Article
Engineering, Chemical
Qing Han, Mengqing Shi, Linkai Han, Di Liu, Mingwei Tong, Yuxin Xie, Zhonghua Xiang
Summary: Developing highly efficient bifunctional oxygen electrocatalysts is crucial for zinc-air flow batteries. Metal-organic frameworks (MOFs) and covalent organic polymers (COPs) have emerged as promising alternatives due to their designable and controllable atomic-level structures. However, their catalytic performances are limited by conductivity and catalytic activity. In this study, nanosheet FeNi-MOF and iron phthalocyanine rich COP hybrid materials are assembled through the pi-pi stacking effect to create highly efficient bifunctional electrocatalysts. The resulting catalyst exhibits superior catalytic performance and stability, making it a promising candidate for zinc-air flow batteries.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Daria Grigorash, Dmytro Mihrin, Rene Wugt Larsen, Erling H. Stenby, Wei Yan
Summary: The article introduces a new approach to describe the cross-association between molecules, allowing for the simulation of weakly bound molecular complexes with different conformations in mixtures. By incorporating this approach into the equation of state, accurate predictions of vapor-liquid equilibrium and liquid-liquid equilibrium can be made. The new method is validated through experiments on alcohol and acid mixtures, with the results compared to experimental data, demonstrating its accuracy and reliability.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Mohammed Al-Sharabi, Daniel Markl, Vincenzino Vivacqua, Prince Bawuah, Natalie Maclean, Andrew P. E. York, Axel Zeitler
Summary: This study used terahertz pulsed imaging to investigate the transport process of different solvents into ceramic catalytic materials. The results showed that the heating rate of the samples influenced the water transport rate, while the viscosity of 1-octanol slowed down its transport.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chukwunonso Anyaoku, Sati Bhattacharya, Rajarathinam Parthasarathy
Summary: This study aimed to enhance understanding of settling dynamics in viscoelastic fluids by developing a semi-empirical correlation and a dimensionless ratio, which accurately described the characteristics of settling suspensions.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Antti I. Koponen, Janika Viitala, Atsushi Tanaka, Baranivignesh Prakash, Olli-Ville Laukkanen, Ari Jasberg
Summary: This study focuses on the development of foam application chemicals for the paper and board industry. The research explores the rheology of the polyvinyl alcohol foam used in the process. Measurements were conducted to determine the foam viscosity and slip flow. The results suggest that slip flow contributes significantly to the total flow rate, and the obtained viscosity and slip models provide a solid foundation for industrial processes.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Dalei Sun, Jinghui Cai, Yating Yang, Zhiwu Liang
Summary: In this study, Fe-doped alpha-Bi2O3 catalysts with different Fe/Bi molar ratios were synthesized and utilized in the carbonylation of isobutyl amine with CO2. The results showed that Fe doping significantly enhanced the catalytic abilities of alpha-Bi2O3.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Yuan Tian, Xinxin Wang, Yanrong Liu, Wenping Hu
Summary: This paper predicts the solubility of nitrogen gas in ionic liquids (ILs) using two quantitative structure-property relationship (QSPR) models. By combining machine learning methods and ionic fragments contribution method, the accuracy and reliability of the prediction models are improved.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Liwang Wang, Wei Liu, Pan Yang, Yulong Chang, Xiaoxu Duan, Lingyu Xiao, Yaoming Hu, Jiwei Wu, Liang Ma, Hualin Wang
Summary: This study investigates the effective phase interfacial area (ae) of hydro-jet cyclones at different injection angles. The results show that a 45 degrees upward incidence angle yields the most favorable flow field characteristics for efficient mass transfer. The significant enhancement in ae of the hydro-jet cyclones offers the advantage of reducing equipment volume and cost savings.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chuanjun Wu, Jiangzhi Chen, Jiyue Sun, I-Ming Chou, Shenghua Mei, Juezhi Lin, Lei Jiang
Summary: In this study, the solubility of H2S hydrate in water was measured using Raman spectroscopy. The results showed that the solubility increases with temperature under certain equilibrium conditions, and the solubility also depends on pressure and temperature under different equilibrium conditions. A thermodynamic model based on the van der Waals-Platteeuw theory was developed to predict the solubility, demonstrating its accuracy.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Lorenzo Brivio, Serena Meini, Mattia Sponchioni, Davide Moscatelli
Summary: This study investigates the influence of three main parameters and proposes a kinetic model to predict the optimal operating conditions for high yield of dimethyl terephthalate (DMT) in the chemical recycling process of polyethylene terephthalate (PET).
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Hongju Lin, Fanhui Liao, Yanchang Chu, Mingyu Xie, Lun Pan, Yuanyuan Wang, Lijian Leng, Donghai Xu, Le Yang, Gangfeng Ouyang
Summary: A honeycomb NiCo/C-Na catalyst with a micro-meso-macroporous structure has been fabricated and shown to have significantly higher catalytic activity for the decarboxylation of fatty acids. It also proves to be efficient in upgrading sludge HTL bio-crude, resulting in a biofuel with decreased viscosity and increased density.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Xiaoxian Li, Rui Li, Min Lin, Mingde Yang, Yulong Wu
Summary: A series of coated non-noble metal porous carbon catalysts were synthesized and applied to the aqueous-phase deoxygenation of algal bio-oil. One of the catalysts showed excellent deoxygenation selectivity and catalytic activity at 250 degrees C. The catalyst exhibited good hydrothermal stability and the reaction mechanism was proposed based on product analysis and active site analysis.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
M. V. Chudakova, M. V. Popov, P. A. Korovchenko, E. O. Pentsak, A. R. Latypova, P. B. Kurmashov, A. A. Pimenov, E. A. Tsilimbaeva, I. S. Levin, A. G. Bannov, A. V. Kleymenov
Summary: A series of catalysts with different potassium contents were prepared using solution combustion synthesis and characterized using various techniques. The results showed that the potassium content affected the phase composition and texture of the catalysts. The addition of a small amount of potassium resulted in a change in particle size distribution, leading to higher hydrogen yield. The Ni-1%K2O/Al2O3 catalyst exhibited the highest hydrogen yield at temperatures of 675 and 750 degrees Celsius.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Aliakbar Roosta, Nima Rezaei
Summary: In this study, we modified the electrolyte cubic plus association equation of state (e-CPA EoS) and integrated it with two electrical conductivity models to estimate the electrical conductivity of 11 monovalent electrolyte solutions in water. The modified e-CPA model demonstrated better performance and the hybridization with electrical conductivity models resulted in two predictive models for estimating the electrical conduction of dilute and concentrated electrolyte solutions. These predictive models showed relative average percentage deviations (AARD) of 11.15% and 13.87% over wide ranges of temperature and electrolyte concentration.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Haoren Niu, Jianzheng Wang, Qingzhu Jia, Qiang Wang, Jin Zhao, Fangyou Yan
Summary: A study developed two quantitative structure-property relationship models for the complexation performance of alpha- and beta-cyclodextrins and validated their stability and predictive ability through internal and external validation. The models showed robustness and satisfactory performance, as demonstrated by the experimental results and model validations. These models can effectively predict the binding constants between cyclodextrins and various types of molecules, providing valuable tools for cyclodextrin design.
CHEMICAL ENGINEERING SCIENCE
(2024)
