Article
Chemistry, Multidisciplinary
Valerie Smejkal, Florian Libisch, Alejandro Molina-Sanchez, Chiara Trovatello, Ludger Wirtz, Andrea Marini
Summary: The study investigates the time evolution of the transient reflection signal in an MoS2 monolayer on a SiO2/Si substrate using first-principles out-of-equilibrium real-time methods, finding that the delayed buildup of the signal is caused by coordinated carrier dynamics and its influence on screening.
Article
Engineering, Multidisciplinary
Tao Cai, Shabnam Mohammadshahi, Taekyung Lee, Kyung Chun Kim
Summary: A 2D phosphorescence-based method was introduced for simultaneous measurement of surface strain and temperature, utilizing sprayed phosphor particles on the test target as sensors. A measurement system with a high-speed camera, LED, and signal generator was established to excite and detect phosphorescence, accurately measuring temperature and strain with an accuracy of 2% and 16% in u-direction and 9.3% in v-direction respectively.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2021)
Article
Thermodynamics
Andreas Kopf, Valerio Frattina, Michele Bardi, Torsten Endres, Gilles Bruneaux, Christof Schulz
Summary: This study presents a two-dimensional thermographic particle image velocimetry (T-PIV) technique for in situ measurement in optically accessible internal combustion (IC) engines. The technique combines temperature and velocity measurements using thermographic phosphor particles as tracers for PIV. The best-suited phosphor material for in-cylinder measurements was identified, and calibration data was generated for signal quantification. The T-PIV technique was successfully applied to obtain instantaneous two-dimensional velocity and temperature fields in the IC engine. However, the technique suffers from low signal intensities at high temperatures, leading to reduced accuracy.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2023)
Article
Engineering, Chemical
Tobias Foller, Huanting Wang, Rakesh Joshi
Summary: This article discusses the potential of novel 2D materials-based membranes in nanofiltration and desalination technologies, highlighting the importance of evaluating critical filtration parameters for membrane performance. It also proposes best-practice methods to accelerate the industrialization of 2D materials-based membranes and suggests the next steps towards real-world applications.
Article
Biology
C. Giannetto, S. Di Pietro, A. Falcone, M. Pennisi, E. Giudice, G. Piccione, G. Acri
Summary: Body temperature is an important indicator of animal health. Rectal thermometry is commonly used in veterinary medicine, but it can be stressful for some animals, particularly cats. Infrared thermal imaging is a less stressful alternative method that has been used in various medical fields for diagnosis and treatment.
JOURNAL OF THERMAL BIOLOGY
(2021)
Article
Thermodynamics
Anthony O. Ojo, David Escofet-Martin, Brian Peterson
Summary: This work presents high-speed 2D wall temperature measurements during flame-wall interaction (FWI) in a narrow channel. The measurements using a phosphor material called Bismuth-doped Scandium vanadate (ScVO4:Bi3+) provide insights into the transient wall heat transfer and flame behavior in micro-combustors and engine crevices. The results show that ScVO4:Bi3+ enables fast measurements with a high temperature sensitivity and good precision. The measurements reveal temperature signatures associated with the FWI events, including unique features in the wall temperature related to wrinkled flame fronts.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Materials Science, Multidisciplinary
J. -l. Dejardin, H. Kachkachi
Summary: This study calculates the heat generated by nanomagnets in an alternating magnetic field and analyzes its transfer to the hosting medium and environment. The heat generated by the nanomagnets is computed using the ac susceptibility, while the heat loss to the environment is modeled using a balance equation based on Newton's law of cooling. The effects of the alternating magnetic field frequency and amplitude on temperature elevation are investigated, and the behavior of Newton's heat transfer coefficient is discussed based on experimental data. The results could contribute to the development of more accurate models for heat generation and diffusion in ferrofluids used in magnetic hyperthermia.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Multidisciplinary Sciences
Christian Gentry, Chen-Ting Liao, Wenjing You, Sinead A. Ryan, Baldwin Akin Varner, Xun Shi, Meng-Xue Guan, Thomas Gray, Doyle Temple, Sheng Meng, Markus Raschke, Kai Rossnagel, Henry C. Kapteyn, Margaret M. Murnane, Emma Cating-Subramanian
Summary: In this study, a newly-developed superlet transform method was used to analyze and extract phonon dynamics in a laser-excited two-dimensional quantum material. The results showed that the superlet transform method is superior in both time and frequency resolution compared to traditional methods, and revealed changes in the coupled dynamics of phonon modes with new physics. This study opens up a new avenue for capturing the coherent evolution and couplings of strongly-coupled materials and quantum systems.
SCIENTIFIC REPORTS
(2022)
Article
Environmental Sciences
Yue Ma, Francis Rose, Leslie Wong, Benjamin Steven Vien, Thomas Kuen, Nik Rajic, Jayantha Kodikara, Wing Kong Chiu
Summary: This paper explores the potential of using a new thermographic approach to identify and monitor scum development under covers in wastewater treatment lagoons. Through experimental testing and finite element modeling, the study demonstrates the reliability of this approach in predicting and monitoring scum accumulation.
Review
Chemistry, Physical
Jieyi Chen, Zihao Zhai, Qi Liu, Huiqiong Zhou
Summary: With the advancement of nanotechnology, quasi two-dimensional (2D) halide perovskites, particularly quasi-2D Dion-Jacobson (DJ) perovskites, have shown remarkable progress in the field of solar cells. These perovskites offer superior stability, high exciton binding energy, and tunable properties. Various strategies have been developed to prepare high-quality quasi-2D DJ perovskites for solar cells, including compositional engineering, solvent engineering, additive addition, and annealing processes. Surface/interface modification and 2D-3D hybrid perovskite heterojunctions are also discussed. Challenges and future perspectives for the development of quasi-2D DJ perovskites for photovoltaics are outlined.
NANOSCALE HORIZONS
(2023)
Article
Engineering, Manufacturing
Lingfeng Shao, Guoqing Xu, Yi Hu
Summary: The article introduces a method based on voltage-rise time and loss of power devices for detection and prediction of junction temperature. The model based on voltage-rise time and loss is verified to have good linearity, fixed sensitivity, and can provide nondestructive IGBT junction temperature extraction through theoretical analysis and simulation verification.
IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY
(2021)
Article
Thermodynamics
Ismael Fernandez-Cuevas, Gonzalo Torres, Manuel Sillero-Quintana, Archit Navandar
Summary: Thermography is commonly used to assess training effects and injury risk after training, but results may vary depending on the time of measurement. This study aimed to determine the hourly variation in skin temperature immediately after strength training and examine bilateral differences in temperature. Fourteen physically active university students participated in a longitudinal study, performing a specific exercise protocol. Results showed a significant decrease in skin temperature immediately after exercise, followed by an increase to pre-exercise levels, and further increases in most cases.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Physics, Applied
J. Lecompagnon, S. Ahmadi, P. Hirsch, C. Rupprecht, M. Ziegler
Summary: Thermographic photothermal super resolution reconstruction allows for the detection and resolution of internal defects/inhomogeneities below the classical limit. It utilizes special sampling strategies and numerical optimization to achieve superior results compared to standard thermographic methods. This work extends the capabilities of the method to efficiently detect and resolve two-dimensional defect cross sections using structured laser-based heating. Two different algorithms are proposed, which utilize convex optimization and take advantage of the sparse nature of defects/inhomogeneities. The algorithms are rated based on reconstruction quality and complexity.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Agriculture, Dairy & Animal Science
Iwona Janczarek, Witold Kedzierski, Ewelina Tkaczyk, Beata Kaczmarek, Jaroslaw Luszczynski, Karolina Mucha
Summary: This study compared the impact of different warm-up regimes on the surface temperature of distal limbs in showjumping horses and leisure horses. The results showed that the surface temperature increase in jumping sport horses was greater than in leisure horses, indicating that the warming-up effect is achieved earlier and lasts longer in heavily trained horses than in non-performance horses.
Article
Engineering, Electrical & Electronic
Juan Antonio Lenero-Bardallo, Rafael De la Rosa-Vidal, Ruben Padial-Allue, Joaquin Ceballos-Caceres, Angel Rodriguez-Vazquez, Jose Bernabeu-Wittel
Summary: A custom system for medical image acquisition and processing has been developed, offering adaptability to different application scenarios. This portable and autonomous system provides immediate results and is cost-effective. Specific algorithms were implemented for two different case studies.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Physical
Hosein Jahangir, Javad Abolfazli Esfahani, Mostafa Pourali, Kyung Chun Kim
Summary: In this study, a computational fluid dynamic (CFD) model is developed to investigate a porous solar propane steam reformer (PSR). The effects of porosity, pore diameter, inlet velocity, solar irradiation flux, inlet temperature, and foam thermal conductivity on the propane conversion, hydrogen production rate, and pressure drop are studied using response surface methodology (RSM). Optimization results show that the reformer with 70% propane conversion provides the lowest pressure drop while maintaining the same hydrogen productivity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Marine
Alireza Aslani, Andrew Shires, Amirreza Shahsavari, Kyung Chun Kim
Summary: The study investigates the aerodynamic performance of a modified NACA 4412 airfoil for circulation control, showing significant increases in lift and reduced take-off distance. The airfoil height has little influence on the efficiency, except under extreme ground effect.
Article
Energy & Fuels
Michael Chukwuemeka Ekwonu, Mirae Kim, Binqi Chen, Muhammad Tauseef Nasir, Kyung Chun Kim
Summary: The parallel expander ORC system improves the partial-load performance of an ORC by switching between various combinations of expanders. This study developed a dynamic model using dual expanders to investigate the dynamic responses during mode changes. Experimental results were used to implement empirical parameters and a control strategy was proposed to prevent droplet formation in the expanders during mode transition. Analysis showed that the optimum shifting time was between 40 to 50 s.
Article
Mechanics
Sajjad Hosseini, Aref Afsharfard, Mehdi Rafati Zarkak, Javad Abolfazli Esfehani, Seungho Kim, Kyung Chun Kim
Summary: The present study investigates the effect of changes on the cross-sectional geometry of a flow-induced vibration-based energy harvester. A bio-inspired geometry, similar to the 'Amaryllis' flower, is utilized for numerical and experimental studies. The study reveals a proportional relation between the enhancement of fluid dynamic forces and the shortening of vortex formation length, and demonstrates that the newly proposed nature-inspired system can effectively increase the amount of harvested energy.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2023)
Article
Thermodynamics
Mohammad Parsa Ghofrani Maab, SayedMehrdad Bathaei, Mirae Kim, Javad Abolfazli Esfahani, Kyung Chun Kim
Summary: This study investigated numerically the ammonia/air premixed combustion in conditions relevant to marine engines. It aimed to gain a deeper understanding of ammonia combustion at high pressure and humidity conditions. The effects of mixture equivalence ratio, compression ratio, and relative humidity on essential combustion characteristics were extensively studied. The results showed that increased air humidity could decrease the laminar flame speed but mitigate NO production, without affecting the reaction pathways.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Computer Science, Interdisciplinary Applications
Shabnam Mohammadshahi, Hadi Samsam-Khayani, Binqi Chen, Tao Cai, Kyung Chun Kim
Summary: This article explores a cost-effective two-dimensional temperature measurement method based on the lifetime technique, which utilizes thermographic phosphor materials to measure surface temperatures. The study analyzes different phosphor-coated samples to study emitted light intensity and temperatures at discrete points. Additionally, a high-speed camera is used to measure surface temperature distributions to ensure coating stability for temperature sensing applications.
JOURNAL OF VISUALIZATION
(2023)
Article
Automation & Control Systems
Yong Eun Lee, Shujun Zhang, Nak Joon Choi, Yoojeong Noh, Kyung Chun Kim
Summary: This study adopts deep learning techniques to detect the misalignment fault of rotating machinery, extracting fault features and reducing dimensions through the t-SNE algorithm, and using the ANN algorithm for fault classification. Compared to the conventional PCA method, the t-SNE algorithm shows higher fault classification accuracy with vibration data.
JOURNAL OF CONTROL AUTOMATION AND ELECTRICAL SYSTEMS
(2023)
Article
Engineering, Mechanical
Golnaz Zarabian Ghaeini, Mohammad Parsa Ghofrani Maab, Sayed Mehrdad Bathaei, Mirae Kim, Javad Abolfazli Esfahani, Kyung Chun Kim
Summary: Ammonia is a promising carbon-free fuel and hydrogen carrier. Blending it with hydrogen can address its low flammability issue. However, there is a lack of microscale data on ammonia combustion. This study uses numerical simulations to investigate the stable flame region, NOx emission, and combustion efficiency of ammonia/hydrogen blends in micro-combustors. The findings suggest that a stable flame cannot be achieved at very low or high inlet velocities, and when the hydrogen fraction is below 60% in the fuel. It is recommended to reduce the inlet velocity to improve combustion efficiency when a higher percentage of ammonia is required in the fuel.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Juyong Jung, Mirae Kim, Tao Cai, Yingzheng Liu, Kyung Chun Kim
Summary: Thermographic phosphor thermometry is a widely used non-contact surface temperature measurement method. The damage of chemical bonding coatings during the measurement often leads to the loss of temperature information. In this study, a deep neural network model was proposed to recover the lost data, achieving a prediction accuracy of over 94.94%. However, the model performed relatively poorly in regions with large temperature gradients.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Chemical
Ahmad Kazemi, Mahmood Norouzi, Ali Abbas Nejad, Mirae Kim, Kyung Chun Kim, Seo Gyun Kim
Summary: This study experimentally investigated the immiscible viscoelastic Saffman-Taylor instability in porous media. The viscoelastic displacing fluids used were glycerin, water, and polyacrylamide solutions, while the immiscible displaced fluids were silicone oils with different viscosities. The study analyzed the role and contribution of the first normal stress difference and elongational viscosity in the immiscible viscoelastic displacement, as well as the effects of different parameters on the flow instability.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Electrochemistry
Sunghwan Oh, Dohyung Kim, Kyung Chun Kim, Doo-In Kim, Wonsub Chung, Byung-Hyun Shin
Summary: Si wafers used in semiconductors require precise machining and are processed using an STS304 saw wire. Recently, the super duplex stainless steel (SDSS) has shown superior performance compared to STS304 and is suitable for use as a saw wire. Nickel plating was applied to ferritized SDSSs to improve the saw wire performance, and the electrochemical properties were analyzed. The optimal duration for electrolytic nickel plating of ferritized SDSS was found to be 240 s.
INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE
(2023)
Article
Thermodynamics
Mohammad Reza Attari, Mahmood Norouzi, Mohammad Hassan Kayhani, Alireza Bakhshinejad Bahambari, Mirae Kim, Kyung Chun Kim
Summary: This study investigates the film cooling performance of oscillating flow on two rows of cooling holes with different arrangements. The results show that flow oscillation can improve the cooling effectiveness of compound angled cooling holes. The frequency of oscillation affects the cooling performance and flow structures.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Mechanics
Mohammad Kazam Sheykhian, Mohammad Hasan Kayhani, Mahmood Norouzi, Mirae Kim, Kyung Chun Kim
Summary: This study investigated the impact of Boger droplets on spherical surfaces, considering the effects of various liquid and surface properties for the first time. The researchers examined the rheological properties of the droplets and analyzed the influence of elasticity, elongational viscosity, and the first normal stress difference on the impact of Boger droplets on solid surfaces. The results were compared to those of equivalent Newtonian droplets in terms of viscosity and surface tension coefficient. Additionally, the study explored the effects of Weber number, diameter ratio, and surface wettability on the spreading and receding behaviors of viscoelastic droplets.
Article
Engineering, Aerospace
Pouya Pouyaei, Mohammad Hassan Kayhani, Mahmood Norouzi, Alireza Bakhshinejad Bahambari, Mirae Kim, Kyung Chun Kim
Summary: This numerical study investigated the effects of a curved turning vane on heat transfer and pressure loss in an internal cooling channel. The results showed that the curved turning vane reduced pressure drop and attenuated overall heat transfer, but increased local heat transfer in specific regions.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING
(2023)
Article
Electrochemistry
Sunghwan Oh, Dohyung Kim, Kyungchun Kim, Doo-In Kim, Wonsub Chung, Byung-Hyun Shin
Summary: This study analyzed the effect of surface roughness on the corrosion resistance and re-passivation of SDSS. The findings showed that surface roughness reduces the corrosion potential and increases the corrosion current density, thereby reducing the corrosion resistance. A surface roughness of less than 100 nm is recommended for better corrosion resistance when using SDSS in a corrosive environment.
INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE
(2023)