Article
Materials Science, Multidisciplinary
Jonathan L. Wise, Nathan Roubinowitz, Wolfgang Belzig, Denis M. Basko
Summary: The noise spectrum of heat current can directly probe the heat-carrying excitations, and our predictions are verified in realistic superconducting circuits and two-dimensional metals. The Landauer-type description for radiative heat transfer breaks down on the level of the noise, while it holds for the average.
Article
Optics
Xiayuqi Yu, Lei Xu, Liying Liu
Summary: We observed strong oscillation intensity modulation in an optomechanical microbubble resonator when two stimulating mechanical modes are weakly coupled. Theoretical expressions of the coupling coefficient between the modes were derived and the region of weak coupling was calculated. Experimental results showed that the two mechanical modes undergo strong intensity modulation as the optical pump power changes, supporting the weak coupling conclusion. Our findings extend the understanding of weak coupling to stimulated oscillation in multiple mechanical modes.
Article
Mechanics
Mehdi Riahi, Mohamed Hayani Choujaa, Said Aniss
Summary: This study investigates two classes of time-periodic Taylor vortex flows: reversing and non-reversing flows. The direction of the vortices in the radial axial-plane either remains conserved or changes every half-cycle/cycle, depending on the frequency of the flow. Using Floquet theory, the counter-oscillation of the outer cylinder is shown to suppress non-reversing flow in certain frequency ranges. The mechanism governing the occurrence of flow reversal in the system is found to depend not only on the oscillation frequency but also on the oscillation of the outer cylinder.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2022)
Article
Physics, Multidisciplinary
Yijun Liu, Xiaohong Yang, Rui Wang, Yongsheng Tang
Summary: The excess noise factor (F) is an important parameter for Avalanche Photodiodes (APDs), indicating the extent to which the noise of the diodes exceeds what it would be without multiplication. This paper presents a method of measuring the excess noise factor for high-speed low-noise APDs using the high-sensitivity spectrum analyzer. The experimental results showed that the F factor for the high-speed InAlAs APD was 3.03 with a multiplication factor M of 10, corresponding to an effective ionization coefficient ratio k of 0.14. In comparison, the k value for a commercial Si APD was tested to be 0.06.
Article
Mathematics, Interdisciplinary Applications
Hassan Arbabi, Themistoklis Sapsis
Summary: This study proposes a data-driven framework to model stationary chaotic dynamical systems through nonlinear transformations and a set of decoupled stochastic differential equations (SDEs). The framework can replicate non-Gaussian statistics and predict super-Gaussian tails efficiently.
SIAM-ASA JOURNAL ON UNCERTAINTY QUANTIFICATION
(2022)
Article
Engineering, Multidisciplinary
Weichao Kuang, Ping Yang, Qing Miao, Wing-Kuen Ling
Summary: A multistage singular spectrum analysis method is proposed to extract useful components from the residue stage step by step. By calculating the spectrum overlap factor, the optimal stage that achieves the highest signal-to-noise ratio is automatically estimated. Simulation results demonstrate that the proposed method has satisfactory denoising performance in various test scenarios.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Civil
Amir Zayeri Baghlani Nejad, Mussa Mahmoudi Sahebi
Summary: The Proper Orthogonal Decomposition (POD) method is commonly used in structural dynamics to extract natural frequencies and damping ratios from experimental vibrational responses. While natural system mode shapes cannot be directly extracted from POD results, good agreement was found between POD-based results and those obtained from traditional methods. In noisy conditions, the accuracy of modal characteristics corresponding to primary natural modes is preserved.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Mechanical
Jian Suo, Haiyan Wang, Xiaohong Shen, Yongsheng Yan, Haitao Dong
Summary: The study proposes a novel method, MIFF-CSR, which uses mutual information and the feed-forward structure of cascaded stochastic resonance to enhance weak signals in underwater sonar. It effectively addresses the challenges of low-frequency interference and resonance effect in large-parameter conditions. Simulations demonstrate its effectiveness and robustness, and application verification experiments validate its practicality and performance improvement.
NONLINEAR DYNAMICS
(2023)
Article
Engineering, Electrical & Electronic
Zhongliang Lv, Linhao Peng, Yujiang Cao, Lin Yang, Linfeng Li, Chuande Zhou
Summary: This article proposes a rolling bearing weak fault feature extraction method based on multiverse optimization algorithm (MVO) optimized MOMEDA under strong noise interference. The method enhances the weak fault signal and performs classification and identification.
IEEE SENSORS JOURNAL
(2023)
Article
Mathematics, Applied
V. V. Ryzhikov
Summary: Unitary flows T-t of dynamical origin are constructed, such that the spectrum of the tensor product circle times(q is an element of Q) T-q is simple, for any countable Q subset of (0,+ infinity). This property holds for all typical flows preserving a sigma-finite measure.
FUNCTIONAL ANALYSIS AND ITS APPLICATIONS
(2022)
Article
Acoustics
Shichun Huang, Xingjian Pan, Liang Yu, Weikang Jiang
Summary: The spinning mode synthesizer is an effective test rig for aero-engine noise research, utilizing calibration factors and Radial Mode Analysis to generate target modes precisely.
Article
Radiology, Nuclear Medicine & Medical Imaging
Ryo Kurokawa, Akifumi Hagiwara, Moto Nakaya, Eriko Maeda, Haruomi Yamaguchi, Wataru Gonoi, Jiro Sato, Kenta Nakata, Kenji Ino, Yoshiaki Ota, Mariko Kurokawa, Akira Baba, Keisuke Nyunoya, Yukiko Usui, Tomoya Tanishima, So Tsushima, Rumiko Torigoe, Takeru Q. Suyama, Osamu Abe
Summary: The study found that reconstruction modes with higher spatial resolution and lower noise reduction can improve the visual assessment of CT images in temporal bone, with CARDIAC SHARP, BONE, and LUNG modes scoring highest on the osseous spiral lamina. Visual scores were significantly correlated with NPSLow, NPSHigh, and 50% modulation transfer function, but negatively correlated with contrast-to-noise ratio.
JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY
(2021)
Article
Neurosciences
Vladimir B. Dorokhov, Anton O. Taranov, Dmitry S. Sakharov, Svetlana S. Gruzdeva, Olga N. Tkachenko, Dmitry S. Sveshnikov, Zarina B. Bakaeva, Arcady A. Putilov
Summary: In this study, a two-dimensionality of individual differences in sleep stages was revealed, suggesting that individual variation in sleep and wake drives associated with the first and second principal components of the EEG spectrum may underlie this structure. Each stage seems to be related to a specific combination of wake-sleep promoting/inhibiting influences associated with these drives for sleep and wake.
JOURNAL OF NEUROPHYSIOLOGY
(2021)
Article
Mathematics, Applied
V. V. Ryzhikov
Summary: This article investigates the properties of flows on disjoint dense subsets of the half-line. The results show that there exists a flow preserving measurability, such that the automorphisms on the dense subset C have simple singular spectrum, while the automorphisms on the dense subset D have Lebesgue spectrum of countable multiplicity.
FUNCTIONAL ANALYSIS AND ITS APPLICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Sudipta Saha, Shoba Krishnan, Allen A. Sweet
Summary: The paper presents a new theoretical framework for calculating the phase noise of LC oscillators to achieve higher oscillator phase noise performance and better insights.
IEEE JOURNAL OF MICROWAVES
(2022)
Article
Robotics
Johan Sundin, Katherine Kokmanian, Matthew K. Fu, Shervin Bagheri, Marcus Hultmark
Summary: This article introduces a new concept of a soft material flow sensor based on elastic filament velocimetry, which meets the requirements for micro air vehicles. The sensor can be manufactured using common laboratory tools, operates with a simple circuit, and allows for sensitivity and bandwidth to be varied by modifying the ribbon's geometry and material properties.
Article
Engineering, Chemical
Y. Sudhakar, Ugis Lacis, Simon Pasche, Shervin Bagheri
Summary: The study develops a homogenized macroscopic model for fluid flows over porous surfaces and provides accurate interface and boundary conditions for handling two- and three-dimensional flows over porous media. The proposed model shows high accuracy in simulating flows over porous and rough walls, as compared to results obtained from geometry-resolved microscopic simulations.
TRANSPORT IN POROUS MEDIA
(2021)
Article
Mechanics
Johan Sundin, Stephane Zaleski, Shervin Bagheri
Summary: Liquid-infused surfaces show promise in reducing friction, fouling, and icing in laminar and turbulent flows, but can experience failure due to capillary waves inducing roughness effects that increase drag in turbulent environments. Energy transfer from turbulent flows to the LIS is explained by the presence of negative curvature in the mean flow at the critical layer, with relations provided to determine whether a LIS behaves as a smooth or rough surface in turbunlent flows based on groove width, Weber number, and friction Reynolds number.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Physics, Multidisciplinary
Hiroki Yasuga, Emre Iseri, Xi Wei, Kerem Kaya, Giacomo Di Dio, Toshihisa Osaki, Koki Kamiya, Polyxeni Nikolakopoulou, Sebastian Buchmann, Johan Sundin, Shervin Bagheri, Shoji Takeuchi, Anna Herland, Norihisa Miki, Wouter van der Wijngaart
Summary: Fluid-fluid interfacial energy drives the emergence of three-dimensional structures in micropillar scaffolds, transforming simple pillars into intricate structures periodic on a microscale. This approach creates structures with internal liquid-liquid interfaces, allowing for applications in liquid-liquid catalysis and the synthesis of novel soft composites.
Article
Mechanics
Sangseung Lee, Jiasheng Yang, Pourya Forooghi, Alexander Stroh, Shervin Bagheri
Summary: This study proposes a transfer learning framework for modeling drag on irregular rough surfaces with a limited dataset. The transfer learning of empirical correlations can improve the performance of neural networks for drag prediction.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Chemistry, Multidisciplinary
Abdul-Raouf Atif, Ugis Lacis, Hakan Engqvist, Maria Tenje, Shervin Bagheri, Gemma Mestres
Summary: In this study, a Langmuir isotherm-based model was utilized to describe protein and cell adhesion on a biomimetic hydroxyapatite surface, showing that increased protein surface coverage enhances cell adhesion and spread, with maximal protein coverage achieved within 48 hours. The Langmuir model demonstrated a good fit with the experimental data, suggesting that computational modeling could lead to time and cost savings in the biomaterial development process.
Article
Mechanics
Johan Sundin, Umberto Ciri, Stefano Leonardi, Marcus Hultmark, Shervin Bagheri
Summary: Liquid-infused surfaces can reduce friction drag and enhance heat transfer, but research in this area is limited. Numerical simulations show that recirculation in the surface texture can lead to increased heat transfer in both laminar and turbulent flows. The contribution of recirculation to heat transfer can be significant in microchannels but is limited in turbulent flows. Nonetheless, a heat transfer enhancement of around 10% is observed in turbulent channel flow.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Seyed Morteza Habibi Khorasani, Ugis Lacis, Simon Pasche, Marco Edoardo Rosti, Shervin Bagheri
Summary: The transpiration-resistance model (TRM) is a set of boundary conditions that can alter near-wall turbulence. It includes slip boundary conditions and a transpiration condition. The transpiration factor, which is the product of slip and transpiration lengths, can be used to characterize rough surfaces.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Ugis Lacis, Michele Pellegrino, Johan Sundin, Gustav Amberg, Stephane Zaleski, Berk Hess, Shervin Bagheri
Summary: The molecular processes of the motion of the contact line were characterized to assess the accuracy of two continuum two-phase models. The calibrated continuum models accurately captured droplet displacement and break-up, but differences were observed near dynamic wetting transitions when compared to atomistic simulations.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Chemistry, Multidisciplinary
Susumu Yada, Ugis Lacis, Wouter van der Wijngaart, Fredrik Lundell, Gustav Amberg, Shervin Bagheri
Summary: This study investigates the impact of droplets on surfaces with inclined micropillars and discovers directional rebound at high impact speeds. The experimental observations are further supported by numerical simulations, revealing the detailed movement of the droplets over the pillars. These findings are significant for the design of structured surfaces to control droplet mobility.
Article
Mechanics
Johan Sundin, Shervin Bagheri
Summary: This study investigates the effects of surfactants on liquid-infused surfaces and finds that they may have more severe impacts compared to superhydrophobic surfaces. An analytical model is constructed to predict the critical surfactant concentration at which the slip length decreases significantly.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Chemical
Si Suo, Haibo Zhao, Shervin Bagheri, Peng Yu, Yixiang Gan
Summary: This study investigates the mobility of droplets trapped within porous surfaces through numerical simulations, identifying three droplet mobility modes and proposing a droplet-scale capillary number for quantitative characterization.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Fisheries
H. Roohi, A. Kideys, S. M. Farabi, M. Rowshan Tabari, G. Finenko, E. Arashkevitch, S. Bagheri, H. Negarestan, M. Rostamian, H. Rostami, R. Pourgholam, T. Shiganova
IRANIAN JOURNAL OF FISHERIES SCIENCES
(2022)
Article
Fisheries
S. Bagheri, S. Khatib, J. Sabkara, Y. Zahmatkesh
IRANIAN JOURNAL OF FISHERIES SCIENCES
(2022)
Article
Fisheries
S. Bagheri, Sayad M. Bourani, H. Babaei, A. Roohi, A. D. Ghandi
Summary: The study investigated changes in abundance of Mnemiopsis leidyi and Beroe ovata near fish cage farming sites in the southwestern Caspian Sea. Results showed that the abundance of both species increased with higher nutrient levels generated from feed and fish excretion, highlighting the importance of understanding the impact of cage culture on local fauna and flora for sustainable development.
IRANIAN JOURNAL OF FISHERIES SCIENCES
(2021)
