Explore the vast range of titles available.

This study develops a vibration model for functionally graded material (FGM) plates with embedded planar cracks. Based on thin plate theory and von Kármán-type geometric nonlinear strain assumptions, the kinetic and potential energies of each region are derived. Displacement field trial functions are constructed according to boundary conditions, and the Ritz method is employed to determine natural frequencies and vibration modes under small deformation conditions. The investigation focuses on how crack parameters and material gradient coefficients affect vibration characteristics in exponentially graded FGM plates. The results show that natural frequencies decrease with increasing crack length, while crack presence alters nodal line patterns and mode symmetry. During free vibration, the upper and lower surfaces of the crack region exhibit relative displacement. Material gradient effects induce thickness–direction asymmetry, causing non-uniform displacements between the plate’s upper and lower sections.

Based on the principles of the discrete element method （DEM）, a scaled-down model was established to analyze burden descending behavior, including asymmetric phenomena, throughout an entire COREX shaft furnace （SF）. The applicability of the DEM model was validated by determining its accordance with a previous experiment. The effects of discharge rate and abnormal conditions on solid flow were described in terms of solid flow pattern and microscopic analysis. Results confirmed that the solid flow of the COREX SF can be divided into four different flow regions; the largest normal force exists at the top of the man-made dead zone, and the weak force network exists in the funnel flow region. The basic solid flow profile was identified as a clear Flat→U→W type. Increasing the dis- charge rate decreased the quasi-stagnant zone size, but did not affect the macroscopic motion of particles or the shape of patterns above the bustle. For asymmetric conditions, in which particles were discharged at different rates, the solid flow patterns were asymmetric. Under an abnormal condition where no particles were discharged from the left outlet, a sizeable stagnant zone was formed opposite to the working outlet, and ＂motionless＂ particles located in the left stagnant zone showed potential to increase the period of static contacts and sticking effect.

The goal of oncological surgery is to completely remove the tumor. Tumors are often difficult to observe with the naked eye because of the presence of numerous blood vessels and the fact the colors of the tumor and blood vessels are similar. Therefore, a fluorescent contrast medium using a surgical microscope is used to observe the removal status of the tumor. To observe the tumor removal status using a fluorescent contrast agent, fluorescence is expressed in the tumor by irradiating with an external light source, and the expressed tumor can be confirmed through a surgical microscope. However, not only fluorescence-expressed tumors are observed under a surgical microscope, but images from an external light source are also mixed and observed. Therefore, since the surgical microscope is connected to a filter, the quality of the diagnostic image is not uniform, and it is difficult to achieve a clear observation. As a result, an asymmetric image quality phenomenon occurs in the diagnostic images. In this paper, a filter with high clarity that provides a symmetrical observation of diagnostic images is developed and manufactured.

This paper deals with peristaltic transport of Phan-Thien-Tanner fluid in an asymmetric channel induced by sinusoidal peristaltic waves traveling down the flexible walls of the channel. The flow is investigated in a wave frame of reference moving with the velocity of the waveby using the long wavelength and low Reynolds number approximations.The nonlinear governing equations are solved employing a perturbation method by choosing as the perturbation parameter. The expressions for velocity, stream function and pressure gradient are obtained. The features of the flow characteristics are analyzed through graphs and the obtained results are discussed in detail. It is noticed that the peristaltic pumping gets reduced due to an increase in the phase difference of the traveling waves. It is also observed that the size of the trapping bolus is a decreasing function of the permeability parameter and the Weissenberg number. Furthermore, the results obtained for the flow characteristics reveal many interesting behaviors that warrant further study on the non-Newtonian fluid phenomena, especially the Peristaltic flow phenomena.

ERA-Interim reanalysis data from the past 35 years have been used with a newly developed feature tracking algorithm to identify Indian monsoon depressions originating in or near the Bay of Bengal. These were then rotated, centralized, and combined to give a fully three-dimensional 106-depression composite structure—a considerably larger sample than any previous detailed study on monsoon depressions and their structure. Many known features of depression structure are confirmed, particularly the existence of a maximum to the southwest of the center in rainfall and other fields and a westward axial tilt in others. Additionally, the depressions are found to have significant asymmetry owing to the presence of the Himalayas, a bimodal midtropospheric potential vorticity core, a separation into thermally cold (~−1.5 K) and neutral (~0 K) cores near the surface with distinct properties, and the center has very large CAPE and very small CIN. Variability as a function of background state has also been explored, with land–coast–sea, diurnal, ENSO, active–break, and Indian Ocean dipole contrasts considered. Depressions are found to be markedly stronger during the active phase of the monsoon, as well as during La Niña. Depressions on land are shown to be more intense and more tightly constrained to the central axis. A detailed schematic diagram of a vertical cross section through a composite depression is also presented, showing its inherent asymmetric structure.

Cuttlefish, a unique group of marine mollusks, produces an internal biomineralized shell, known as cuttlebone, which is an ultra-lightweight cellular structure (porosity, ∼93 vol%) used as the animal’s hard buoyancy tank. Although cuttlebone is primarily composed of a brittle mineral, aragonite, the structure is highly damage tolerant and can withstand water pressure of about 20 atmospheres (atm) for the species Sepia officinalis. Currently, our knowledge on the structural origins for cuttlebone’s remarkable mechanical performance is limited. Combining quantitative three-dimensional (3D) structural characterization, four-dimensional (4D) mechanical analysis, digital image correlation, and parametric simulations, here we reveal that the characteristic chambered “wall–septa” microstructure of cuttlebone, drastically distinct from other natural or engineering cellular solids, allows for simultaneous high specific stiffness (8.4 MN·m/kg) and energy absorption (4.4 kJ/kg) upon loading. We demonstrate that the vertical walls in the chambered cuttlebone microstructure have evolved an optimal waviness gradient, which leads to compression-dominant deformation and asymmetric wall fracture, accomplishing both high stiffness and high energy absorption. Moreover, the distribution of walls is found to reduce stress concentrationswithin the horizontal septa, facilitating a larger chamber crushing stress and a more significant densification. The design strategies revealed here can provide important lessons for the development of low-density, stiff, and damage-tolerant cellular ceramics.

Low back joint compression forces have been linked to the development of chronic back pain. Back-support exoskeletons controllers based on low back compression force estimates could potentially reduce the incidence of chronic pain. However, progress has been hampered by the lack of robust and accurate methods for compression force estimation. Electromyography (EMG)-driven musculoskeletal models have been proposed to estimate lumbar compression forces. Nonetheless, they commonly underrepresented trunk musculoskeletal geometries or activation–contraction dynamics, preventing validation across large sets of conditions. Here, we develop and validate a subject-specific large-scale (238 muscle–tendon units) EMG-driven musculoskeletal model for the estimation of lumbosacral moments and compression forces, under eight box-lifting conditions. Ten participants performed symmetric and asymmetric box liftings under 5 and 15 kg weight conditions. EMG-driven model-based estimates of L5/S1 flexion–extension moments displayed high correlation, R2 (mean range: 0.88–0.94), and root mean squared errors between 0.21 and 0.38 Nm/kg, with respect to reference inverse dynamics moments. Model-derived muscle forces were utilized to compute lumbosacral compression forces, which reached eight times participants body weight in 15 kg liftings. For conditions involving stooped postures, model-based analyses revealed a predominant decrease in peak lumbar EMG amplitude during the lowering phase of liftings, which did not translate into a decrease in muscle–tendon forces. During eccentric contraction (box-lowering), our model employed the muscle force–velocity relationship to preserve muscle force despite significant EMG reduction. Our modeling methodology can inherently account for EMG-to-force non-linearities across subjects and lifting conditions, a crucial requirement for robust real-time control of back-support exoskeletons.

In boreal winter, the El Niño/Southern Oscillation (ENSO)‐induced Pacific‐North American (PNA) teleconnection pattern is farther westward during La Niña relative to that in El Niño, causing discernible distinct climate implications. However, there has been a lack of consensus regarding the underlying mechanism driving this asymmetric structure. This study highlights the contribution of nonlinear kinetic energy advection (nKA) to this asymmetry. The zonally symmetric responses to ENSO, specifically the anomalies in zonal mean zonal flow, generate opposing nKA patterns by advecting anomalous eddy kinetic energy in the North Pacific, which leads to the shift of the PNA teleconnection pattern. In addition to nKA, transient eddy activities responded to changes of baroclinicity help maintain the asymmetry through a feedback effect. These findings underscore the importance of considering extratropical factors, such as nonlinear energy processes and synoptic‐scale transient eddies, in understanding the mechanism responsible for the asymmetric structure of the PNA teleconnection pattern. Plain Language Summary The El Niño/Southern Oscillation (ENSO)‐induced atmospheric anomalies over the North Pacific and North America (PNA region) are more westward during La Niña relative to that during El Niño in boreal winter. The disparity of atmospheric responses causes discernible distinct climate implications, and limits the seasonal prediction. The mechanism underlying this asymmetry, however, remains in disagreement. Some believe that it is due to variations in the location of tropical convective anomalies. Whereas others show that the climatological zonal flow could anchor the disturbance. Utilizing a more comprehensive energy diagnostic framework, we find that the nonlinear component, in particular, the nonlinear kinetic energy advection and the feedback effect of synoptic‐scale disturbances contribute to the asymmetric atmospheric responses. The study emphasizes the importance of nonlinear processes and multi‐scale interactions in the asymmetric structure of ENSO‐induced atmospheric anomalies in the PNA region, which are essential for understanding ENSO teleconnections, comprehending model biases, and improving seasonal predictions. Key Points The El Niño/Southern Oscillation‐induced Pacific‐North American (PNA) teleconnection pattern is farther westward during La Niña relative to that in El Niño The nonlinear energy advection redistributes the kinetic energy, hence contributing to the asymmetric PNA teleconnections Different synoptic‐scale transient eddy activities help to maintain and amplify the asymmetry through a feedback effect

Nonlinear dynamical systems with symmetry have been studied extensively yielding rich and striking bifurcation patterns such as period-doubling sequence, merging crisis, crisis-induced intermittency, spontaneous symmetry breaking, and coexisting pairs of mutually symmetric attractors as well. However, very little is known unfortunately about the behavior of such systems in the presence of an explicit symmetry breaking perturbation. In this work, we evaluate the impact of an explicit symmetry break on the dynamics of a fourth-order autonomous memristive chaotic circuit. The symmetry break is obtained by assuming different electrical properties for the two pairs of diodes forming the generalized memristor. Thus, the generalized memristor exhibits an asymmetric pinched hysteresis loop which induces the asymmetry of the whole jerk circuit. We demonstrate that the symmetry break induces new and extremely complex patterns including critical phenomena, coexisting bubbles of different periodicity, multiple coexisting nonsymmetric attractors, just to name a few. These features are highlighted by using phase portraits, basins of attraction, bifurcation diagrams, and plots of largest Lyapunov exponents as main tools. A series of laboratory experimental tests are carried out to support the theoretical analysis.

This scheme proposes for the first time a hierarchical quantum information transmission scheme for asymmetric bidirectional transmission of unknown single particle quantum states and two particle quantum states with four communication participants. During the communication process, the communication party undertaking ordinary tasks can only complete information transmission under the supervision of one controller, while the communication party performing important tasks can only complete information transmission with the permission and assistance of two controllers. The scheme also discusses the selection of participants who communicate with Alice while the quantum channel remains unchanged.