Dissipation Research Articles

A submesoscale eddy identification dataset in the northwest Pacific Ocean derived from GOCI I chlorophyll a data based on deep learning

Abstract. This paper presents a dataset on the identification of submesoscale eddies, derived from high-resolution chlorophyll a data captured by GOCI I in the northwest Pacific Ocean. Our methodology involves a combination of digital image processing, filtering, and object detection techniques, along with a specific chlorophyll a image enhancement procedure to extract essential information about submesoscale eddies. This information includes their time, polarity, geographical coordinates of the eddy center, eddy radius, coordinates of the upper left and lower right corners of the prediction box, area of the eddy's inner ellipse, and confidence score. The dataset spans eight time intervals, ranging from 00:00 to 08:00 (UTC) daily, covering the period from 1 April 2011 to 31 March 2021. A total of 19 136 anticyclonic eddies and 93 897 cyclonic eddies were identified, with a minimum confidence threshold of 0.2. The mean radius of anticyclonic eddies is 24.44 km (range 2.5 to 44.25 km), while that of cyclonic eddies is 12.34 km (range 1.75 to 44 km). This unprecedented hourly resolution dataset on submesoscale eddies offers valuable insights into their distribution, morphology, and energy dissipation. It significantly contributes to our understanding of marine environments, ecosystems, and the improvement of climate model predictions. The dataset is available at https://doi.org/10.5281/zenodo.13989785 (Wang and Yang, 2023).

Real-time control of non-Abelian anyons in Kitaev spin liquid under energy dissipation

Real-time control of non-Abelian anyons in Kitaev spin liquid under energy dissipation

CMOS Comparator Design using 90nm Technology

In many digital circuits the parameters gain and offset voltage are calculated. In our design of CMOS comparator with high performance using GPDK 90nm technology we optimize these parameters. The gain is calculated in AC analysis and also we measure area, delay, power dissipation, slew rate, rise time, fall time. The circuit is built by using PMOS and NMOS transistor with a body effect and we also measure mobility variation and channel length modulation based on the second order channel effects. A plot of gain and offset voltage also discussed in the paper. Finally a test schematic is built and transient analysis for an input voltage of 1.2V is measured using Cadence virtuoso.

Impact Resistance of Layered Aramid Fabric: A Numerical Study on Projectile-Induced Damage

The aim of this work is to comparatively analyze, using numerical simulation, the impact behavior of aramid fabric. A layered panel was impacted by two projectiles specific to the NIJ protection level HG1. The protection level in this study is based on NIJ Standard 0123.00. This standard is used to establish protection levels. The two projectiles specific to the NIJ HG1 protection level are 9 mm Luger and .357 Mag FMJ. Law enforcement personnel use body armor designed to protect the torso. With the help of numerical simulation, the mechanisms of destruction of the aramid fabric on impact are identified. The protection performance is analyzed as a function of the influence of the number of layers and the projectile velocity variation. The fabric is modeled at the yarn level, with each yarn consisting of hundreds or even thousands of fibers. Simulations are performed at the yarn level, since fiber-level modeling is difficult to implement due to high computational resource requirements. The material properties for the yarn, as well as for the projectiles, are selected from the literature. The results show that only the 20-layer fabric panel impacted by the 9 mm Luger FMJ RN 9 mm FMJ RN projectile at 398 m/s meets the protection requirements of the NIJ standard (NIJ HG1 protection level). In contrast, panels impacted at 436 m/s, or those with fewer layers, show rapid stress wave propagation, severe deformation, and complete perforation, indicating insufficient energy dissipation. This study highlights the critical role of impact velocity, projectile geometry, and number of layers in determining ballistic resistance. These findings contribute to the development of more effective ballistic protective equipment, highlighting the need for optimized layer configurations and improved material properties to meet NIJ standards under different impact conditions.

Controllable Self-Assembly of V═O Metalloradical Complex with Intramolecular Charge Transfer for Enhanced NIR-II Fluorescence Imaging-Guided Photothermal Therapy.

Near-infrared second region (NIR-II) fluorescence imaging provides enhanced tissue penetration, achieving efficient NIR-II fluorescence and photoacoustic imaging (PA)-guided photothermal therapy (PTT) all in one material remains a challenging yet promising approach in cancer treatment. Herein, open-shell V═O metalloradical complex (VONc) is self-assembled into VONc nanospheres (VONc NPs). VONc NPs exhibit light absorption from 300 to 1400 nm, fluorescence spectra ranging from 900 to 1400 nm, and a distinct fluorescence signal even at 1550 nm. Moreover, VONc NPs exhibit outstanding photostability and a higher photothermal conversion efficiency of 46.6% than that of closed-shell zinc naphthalocyanine nanorods (ZnNc NRs). V═O centered metalloradical serves as transient electron-withdrawing groups to facilitate charge transfer (CT), introducing additional nonradiative energy dissipation pathways and enhancing efficient heat generation. In vitro experiments of VONc NPs indicate that a highly effective photothermal action causes harm to both mitochondria and lysosomes, resulting in the death of tumor cells, closed-shell ZnNc NPs exhibit almost no cell killing as contrast. In vivo anti-tumor therapy results of VONc NPs demonstrate excellent NIR-II fluorescence imaging-guided PTT against tumors with a favorable biosafety profile. "Centered metalloradical boosting CT" toward open-shell metal complexes provides significant insight for developing single-material integrated nanosystems for diagnostic and therapeutic applications.

Temporal Changes of Downstream Land of a Culvert: The Effect of an Installation of Energy Dissipator

Temporal Changes of Downstream Land of a Culvert: The Effect of an Installation of Energy Dissipator

Impact of CFRP Strengthening on the flexural behavior of reinforced concrete beams

ABSTRACTReinforced concrete structures often experience damage and a degradation in performance under external loads. Consequently, it is crucial to enhance their performance through appropriate reinforcement techniques. Fiber-reinforced polymer composites (FRP) have gained significant attention in structural engineering due to their distinct advantages over traditional steel reinforcement. FRP reinforcement can be applied via near-surface mounted (NSM) or external bonding (EBR) methods, with the latter being more commonly used. This study examines the impact of CFRP reinforcement on the flexural performance of reinforced concrete beams, with particular emphasis on the ductile behavior required for seismic energy dissipation and load redistribution in hyperstatic structures. An analytical expression linking the level of ductility to the reinforcement ratio is proposed. This relationship can serve as a valuable tool in the reinforcement design process.

Light-Powered Self-Translation of an Asymmetric Friction Slider Using a Liquid Crystal Elastomer String Oscillator

In recent years, there have been many studies focused on improving the performance of active materials; however, applying these materials to active machines still presents significant challenges. In this study, we introduce a light-powered self-translation system for an asymmetric friction slider using a liquid crystal elastomer (LCE) string oscillator. The self-translation system was composed of a hollow slide, two LCE fibers, and a mass ball. Through the evolution of photothermal-induced contraction, we derived the governing equations for the system. Numerical simulations revealed two distinct motion modes: the static mode and the self-translation mode. As the mass ball moved, the LCE fibers alternated between illuminated and non-illuminated states, allowing them to effectively harvest light energy to compensate for the energy dissipation within the system. Unlike traditional self-oscillating systems that oscillate around a fixed position, the asymmetric friction enabled the slider to advance continuously through the oscillator’s symmetric self-sustained oscillation. Furthermore, we explored the critical conditions necessary for initiating self-translation as well as key system parameters that influence the frequency and amplitude of the oscillator and average speed of the slider. This self-translation system, with its simple design and ease of control, holds promising potential for applications in various fields including soft robotics, energy harvesting, and active machinery.

Constructing High-Performance Composite Epoxy Resins: Interfacial π-π Stacking Interactions-Driven Physical Rolling Behavior of Silica Microspheres.

The intrinsic compromise between strength and toughness in composite epoxy resins significantly constrains their practical applications. In this study, a novel strategy is introduced, leveraging interfacial π-π stacking interactions to induce the "rolling behavior" of microsphere fillers, thereby facilitating efficient energy dissipation. This approach is corroborated through theoretical simulations and experimental validation. The resulting composite epoxy resin demonstrates an impressive 49.8% enhancement in strength and a remarkable 358.9% improvement in toughness compared to conventional epoxy resins, accompanied by substantially reduced hysteresis. Moreover, this system achieves reversible closed-loop recyclability and rapid repair capabilities. The preliminary demonstration of "force-temperature equivalence" further establishes a novel pathway for the design of high-performance composite epoxy materials.

Experimental Investigation of Embedment Depth Effects on the Rocking Behavior of Foundations

Shallow foundations supporting high-rise structures are often subjected to extreme lateral loading from wind and seismic activities. Nonlinear soil–foundation system behaviors, such as foundation uplift or bearing capacity mobilization (i.e., rocking behavior), can act as energy dissipation mechanisms, potentially reducing structural demands. However, such merits may be achieved at the expense of large residual deformations and settlements, which are influenced by various factors. One key factor which is highly influential on soil deformation mechanisms during rocking is the foundation embedment depth. This aspect of rocking foundations is investigated in this study under varying subgrade densities and initial vertical factors of safety (FSv), using the PIV technique and appropriate instrumentation. A series of reduced-scale slow cyclic tests were performed using a single-degree-of-freedom (SDOF) structure model. This study first examines the deformation mechanisms of strip foundations with depth-to-width (D/B) ratios of 0, 0.25, and 1, and then explores the effects of embedment depth on the performance of square foundations, evaluating moment capacity, settlement, recentering capability, rotational stiffness, and damping characteristics. The results demonstrate that the predominant deformation mechanism of the soil mass transitions from a wedge mechanism in surface foundations to a scoop mechanism in embedded foundations. Increasing the embedment depth enhances recentering capabilities, reduces damping, decreases settlement, increases rotational stiffness, and improves the moment capacity of the foundations. This comprehensive exploration of foundation performance and soil deformation mechanisms, considering varying embedment depths, FSv values, and soil relative densities, offers insights for optimizing the performance of rocking foundations under lateral loading conditions.

Tough and Stretchable Zwitterionic Eutectogels via Copolymerization-Induced Phase Separation in a Targeted Deep Eutectic Solvent.

Deep eutectic solvent (DES)-based eutectogels show significant promise for flexible sensors due to their high ionic conductivity, non-volatility, biocompatibility, and cost-effectiveness. However, achieving tough and stretchable eutectogels is challenging, as the highly polar DES tends to screen noncovalent bonds, such as hydrogen and ionic bonds, between polymer chains, limiting their mechanical strength. In this work, this issue is addressed by leveraging the limited solubility of zwitterionic polymers in a specific DES to induce phase separation, promoting dipole-dipole interactions between polymer chains. These interactions improve energy dissipation under mechanical stress, allowing the creation of tough and stretchable P(MAA-co-VIPS)/TBAC-EG eutectogels through a copolymerization-induced phase separation approach. Methacrylic acid (MAA) and sulfobetaine vinylimidazole (VIPS) are copolymerized within a tetrabutylammonium chloride-ethylene glycol (TBAC-EG) DES, resulting in a bicontinuous network. The bicontinuous structure consists of a PVIPS-rich phase that enhances toughness via dipole-dipole interactions, and a PMAA solvent-rich phase that enables high stretchability. The resulting eutectogel demonstrates excellent mechanical properties, including a strength of 1.76MPa, toughness of 16.61MJ m⁻3, and remarkable stretchability of 1293%, along with self-recovery, self-healing, and shape-memory capabilities. The zwitterionic polymer-specific DES design opens up broad application potential for these eutectogels in diverse fields.

The interplay of energy and motion of coupled pendulums: a high school student exploration

Abstract The experiment of string-coupled pendulums offers high school students a hands-on opportunity to explore fundamental principles of physics while developing critical skills. In this experiment, students investigate how an oscillating pendulum transfers kinetic energy to a stationary one, resulting in a cyclical exchange marked by role reversals. The motion of the coupled pendulum is studied using a simple smartphone equipped with free software. Pendulums of equal length and point-mass are arranged in three different configurations: pendulum on a fixed rod, pendulum on a string, and string-coupled pendulum. These configurations not only exhibit varying time periods but also significantly different amplitude decay patterns. Despite inevitable energy dissipation due to frictional losses and air resistance, the oscillations exhibited by the coupled pendulums clearly demonstrate the interplay between synchronization and energy transfer. This initial hands-on investigation serves as a springboard for a more comprehensive exploration of the captivating energy transfer mechanisms and dynamical characteristics inherent to string-coupled pendulums.

RESEARCH OF ENERGY DISSIPATION ACCORDING TO THE DISCRETE-CONTINUUM MODEL OF A TWO-PLACE VIBRATION SYSTEM

In the work, the energy of the oscillation process was investigated according to the discrete model of the two-seat vibration system "working body of the machine - sealing medium". It was found that with a small dissipation of energy in the case of a force acting on one of the masses at a given amplitude of oscillations of this mass, the ratio of amplitudes of oscillations in the resonance mode is determined only by the parameters of the second mass and the ratio between the masses. The conditions for the effect of dissipation in the resonance mode at a frequency close to the partial frequency of the mass on which the external force acts are determined. At the same time, the difference between the inertial force acting on the second mass and the elastic force is not equal to zero. Therefore, the effect of dissipation is negligible. In the case of resonance at the frequency caused by the second mass, the role of scattering forces increases. The energy dissipation associated with the mass on which an external force acts has a significant effect on the frequency of the first resonance. The obtained research results are important information for the design of vibration machines of this class, including surface machines for laying concrete roads.

Effects of Thermal and Stress Cycles on the Mechanical Properties and Acoustic Emission Characteristics of Rocks

Abstract The surrounding rock of underground rock chamber is frequently affected by disturbance load and circulating temperature; it is meaningful to study the mechanical properties of surrounding rock under these conditions for the construction of a safe and effective underground chamber. This study investigates the mechanical properties, failure modes, and acoustic emission (AE) characteristics of basalt and sandstone under various pretreatments, including water saturation pretreatment (rock samples [SR]), rock samples subjected to cyclic temperature pretreatment (SR-CTT), rock samples subjected to cyclic loading pretreatment (SR-CLT), and rock samples subjected to combined cyclic loading and temperature pretreatment (SR-CTT-CLT). A series of uniaxial compression tests (UCTs) were conducted to analyze how these pretreatments affect the mechanical properties of basalt and sandstone. These two kinds of rock exhibit distinct failure modes, SR-CLT and SR-CTT-CLT make the failure of basalt change from inclined shear to X-shaped shear, while SR-CLT makes it turn into splitting. AE data reveal that basalt generally exhibits lower AE counts than sandstone, with the highest counts observed under SR-CTT-CLT. Energy analysis indicates that basalt accumulates more total energy (Et) and elastic energy (Ee) compared to sandstone, with different pretreatments affecting energy dissipation (Ed) and damage severity differently in each rock type. These findings contribute to understanding the complex interactions between pretreatment methods and rock behavior in engineering applications.

Comparative Analysis of the Seismic Behavior of a Ported Housing applying Energy Dissignants

The objective of this article is to compare the seismic behavior of two types of energy dissipators applied in a multi-family home: the viscous fluid dissipator and the Shear Link Bozzo (SLB) dissipator. The methodology used is a quantitative and descriptive approach, which allows a detailed structural evaluation of both systems. Two dissipative models are included in the analysis: one traditional, which uses viscous fluid heatsinks, and another contemporary, based on SLB heatsinks. The Tacna accelerometric records were used with an earthquake intensity of 6.2, this for both heatsinks. The results indicate that the viscous fluid dissipator significantly reduces structural drift, with 84.15% in the the structure. For its part, the model with SLB heatsinks achieves an even greater reduction in drift, reaching 91.86% in the X direction and 95.94% in the Y direction, also used in columns and beams. This system demonstrates superior performance in terms of seismic control, providing optimized structural protection. It is concluded that, through a comparative analysis between the 2 modeling, the SLB heatsink presents optimal performance, positioning it as an effective alternative for seismic protection in similar multifamily buildings, contributing to structural safety and social well-being in seismic contexts.

Energy Dissipation in Strong Collisionless Shocks: The Crucial Role of Ion-to-electron Scale Separation in Particle-in-cell Simulations

Abstract Energy dissipation in collisionless shocks is a key mechanism in various astrophysical environments. Its nonlinear nature complicates analytical understanding and necessitates particle-in-cell (PIC) simulations. This study examines the impact of reducing the ion-to-electron mass ratio (m r ), to decrease computational cost, on energy partitioning in one spatial and three velocity-space dimension PIC simulations of strong, nonrelativistic, parallel electron–ion collisionless shocks using the SHARP code. We compare simulations with a reduced mass ratio (m r = 100) to those with a realistic mass ratio (m r = 1836) for shocks with high ( M A = 21.3 ) and low ( M A = 5.3 ) Alfvén Mach numbers. Our findings show that the mass ratio significantly affects particle acceleration and thermal energy dissipation. At high M A , a reduced mass ratio leads to more efficient electron acceleration and an unrealistically high ion flux at higher momentum. At low M A , it causes complete suppression of electron acceleration, whereas the realistic mass ratio enables efficient electron acceleration. The reduced mass ratio also results in excessive electron heating and lower heating in downstream ions at both Mach numbers, with slightly more magnetic field amplification at low M A . Consequently, the electron-to-ion temperature ratio is high at low M A due to reduced ion heating and remains high at high M A due to increased electron heating. In contrast, simulations with the realistic m r show that the ion-to-electron temperature ratio is independent of the upstream magnetic field, a result not observed in reduced m r simulations.

A study on martensitic transformation behavior in shape memory alloys via a modulated differential scanning calorimetry technique

Highly precise and efficient characterization of thermophysical parameters associated with martensitic transformation (MT) in shape memory alloys (SMA) is challenging based on conventional calorimetry methods. Moreover, existing methods for evaluating the elastocaloric effect of SMA typically require a series of tests and calculations. In addition, the present method cannot evaluate the nonreversible part during MT. This work proposed a technique rarely mentioned in previous studies on martensitic transformation of metals and alloys, i.e., utilizing the modulated differential scanning calorimetry (MDSC) to superimpose a sinusoidal signal over an underlying DSC ramp. By adjusting appropriate measurement parameters, the reversible and nonreversible parts of thermal events during MT of SMAs were revealed. Furthermore, a series of thermal parameters useful for the study of MT can be obtained by this method and thus may provide a perspective for studying the MT process. Based on MDSC technique, we took Ni-Mn-Sn-(Cu) alloys, a kind of ferromagnetic shape memory alloy, as an example to demonstrate the study of the MT process as well as the elastocaloric effect. From the perspective of energy dissipation, we analyzed the intrinsic relationship between nonreversible component and thermal hysteresis in the MT process. Conventional DSC test and experimental results on the adiabatic temperature change (ΔTad) were also provided to verify the MDSC prediction results.

Modeling and Optimization of Regenerative MacPherson Strut

<div>Throughout the vehicles industry and electrification, vehicle ride comfort, road holding, and fuel/charge economy have always been important considerations for the design and development of shock absorbers. Vehicle suspension is one of the oscillating power dissipation sources in which the undesired mechanical energy is dissipated into heat waste. Therefore, in this study a regenerative MacPherson strut is modeled and validated to investigate the vehicle vertical dynamics performance as well as the harvestable power that can be used to charge batteries or power vehicle electrical loads. The optimal design parameters of the regenerative MacPherson strut (RE.M.S) is obtained by using multi-object genetic algorithm (MOGA) optimization for a better trade-off between regenerated power, ride comfort, and road holding. The results showed that RE.M.S can function as a semi-active shock absorber as change of duty cycle of charging circuit. Furthermore, the optimal selection of the design parameters such as the inclination angle of the MacPherson strut and the external load have a very significant effect to stabilize the level of the harvested regenerated power, ride comfort, and road holding at different driving conditions.</div>

Parameter Analysis of Resilient Precast Concrete Beam–Column Joints

Conventional precast structures often face the challenge of post-earthquake repair, especially at beam–column joints. A new type of precast concrete beam–column joint with a replaceable energy dissipation device consisting of cross-shaped and H-shaped steel was proposed in this paper, which was characterized by the use of replaceable energy-dissipating devices to improve the seismic capacity. Based on the previous test results of the group, this paper used ABAQUS to investigate how factors like the thickness of the H-shaped steel webs and the size and number of openings affected the seismic performance of precast concrete beam–column joints with replaceable energy dissipation devices. The results showed that (1) an increase in the H-shaped steel’s thickness in the REDDC could improve the load-carrying capacity of the node, but the energy dissipation capacity was weakened, and (2) the length and width of the H-shaped steel openings had almost no effect on the ultimate load-carrying capacity within a certain range, but increasing the size of the openings could improve the energy dissipation capacity and reduce the ultimate load-carrying capacity at the same time. Compared with the length of the openings, the width of the openings had a more significant impact on the energy dissipation capacity. (3) The peak load-carrying capacity decreased with an increase in the number of openings in the H-shaped steel.

Non-linear saturation and energy transport in global simulations of magneto-thermal turbulence in the stratified intracluster medium

The magneto-thermal instability (MTI) is one of many possible drivers of stratified turbulence in the intracluster medium (ICM) outskirts of galaxy clusters, where the background temperature gradient is most likely aligned with the gravity. This instability occurs because of the fast anisotropic conduction of heat along magnetic field lines. However, the extent to which it impacts the ICM dynamics, energetics, and overall equilibrium is still a matter of debate. This work aims to understand MTI turbulence in an astrophysically stratified ICM atmosphere, its underlying saturation mechanism, and its ability to carry energy and to provide non-thermal pressure support. We performed a series of 2D and 3D numerical simulations of the MTI in global spherical models of a stratified ICM thanks to the finite-volume Godunov-type code IDEFIX and using Braginskii magnetohydrodynamics. We used well-controlled volume-averaged, shell-averaged, and spectral diagnostics to study the saturation mechanism of the MTI and its radial transport energy budget. The MTI is found to saturate through a dominant balance between injection and dissipation of available potential energy, which amounts to marginalising the Braginskii heat flux but not the background temperature gradient itself. Accordingly, the strength and injection length of MTI-driven turbulence exhibit clear dependencies on the thermal diffusivity. With realistic Spitzer conductivity, the MTI drives cluster-size motions with Mach numbers up to $ M 0.3$, even in the presence of strong stable entropy stratification. We show that such mildly compressible flows can provide about $ 15<!PCT!>$ of the non-thermal pressure support in the outermost ICM regions close to the cluster accretion shock and that the convective transport itself is much less efficient (a few percent only) than conduction at radially transporting energy. Finally, we show that the MTI saturation can be described by a diffusive mixing-length theory, shedding light on the diffusive buoyant nature, rather than the adiabatic convective nature, of the instability. The MTI seems relevant to both the dynamics and energetics of the ICM through radially biased magnetic fields that enhance the background Braginskii heat flux. Further work including externally forced turbulence, for instance, mimicking accretion-induced turbulence, is needed to assess its overall relative importance in comparison to other drivers of ICM turbulence.