Hydrodynamics of a floating barge adjacent to fixed structure in transient wave fronts

2021 ◽  
Vol 33 (10) ◽  
pp. 107106
Author(s):  
Chongwei Zhang ◽  
Xiaotong Sun ◽  
Zhenyu Ding ◽  
Lifen Chen ◽  
Dezhi Ning
2006 ◽  
Vol 290 (5) ◽  
pp. C1411-C1427 ◽  
Author(s):  
Kyu Joo Park ◽  
Grant W. Hennig ◽  
Hyun-Tai Lee ◽  
Nick J. Spencer ◽  
Sean M. Ward ◽  
...  

Spontaneous electrical pacemaker activity occurs in tunica muscularis of the gastrointestinal tract and drives phasic contractions. Interstitial cells of Cajal (ICC) are the pacemaker cells that generate and propagate electrical slow waves. We used Ca2+ imaging to visualize spontaneous rhythmicity in ICC in the myenteric region (ICC-MY) of the murine small intestine. ICC-MY, verified by colabeling with Kit antibody, displayed regular Ca2+ transients that occurred after electrical slow waves. ICC-MY formed networks, and Ca2+ transient wave fronts propagated through the ICC-MY networks at ∼2 mm/s and activated attached longitudinal muscle fibers. Nicardipine blocked Ca2+ transients in LM but had no visible effect on the transients in ICC-MY. β-Glycyrrhetinic acid reduced the coherence of propagation, causing single cells to pace independently. Thus, virtually all ICC-MYs are spontaneously active, but normal activity is organized into propagating wave fronts. Inhibitors of dihydropyridine-resistant Ca2+ entry (Ni2+ and mibefradil) and elevated external K+ reduced the coherence and velocity of propagation, eventually blocking all activity. The mitochondrial uncouplers, FCCP, and antimycin and the inositol 1,4,5-trisphosphate receptor-inhibitory drug, 2-aminoethoxydiphenyl borate, abolished rhythmic Ca2+ transients in ICC-MY. These data show that global Ca2+ transients in ICC-MYs are a reporter of electrical slow waves in gastrointestinal muscles. Imaging of ICC networks provides a unique multicellular view of pacemaker activity. The activity of ICC-MY is driven by intracellular Ca2+ handling mechanisms and entrained by voltage-dependent Ca2+ entry and coupling of cells via gap junctions.


2020 ◽  
Author(s):  
Laura V. Young ◽  
Alasdair WR Cameron ◽  
Stevan SA Springer ◽  
Joel Ross ◽  
Grant Wolters ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Denis V. Novitsky ◽  
Dmitry Lyakhov ◽  
Dominik Michels ◽  
Dmitrii Redka ◽  
Alexander A. Pavlov ◽  
...  

AbstractUnique and flexible properties of non-Hermitian photonic systems attract ever-increasing attention via delivering a whole bunch of novel optical effects and allowing for efficient tuning light-matter interactions on nano- and microscales. Together with an increasing demand for the fast and spatially compact methods of light governing, this peculiar approach paves a broad avenue to novel optical applications. Here, unifying the approaches of disordered metamaterials and non-Hermitian photonics, we propose a conceptually new and simple architecture driven by disordered loss-gain multilayers and, therefore, providing a powerful tool to control both the passage time and the wave-front shape of incident light with different switching times. For the first time we show the possibility to switch on and off kink formation by changing the level of disorder in the case of adiabatically raising wave fronts. At the same time, we deliver flexible tuning of the output intensity by using the nonlinear effect of loss and gain saturation. Since the disorder strength in our system can be conveniently controlled with the power of the external pump, our approach can be considered as a basis for different active photonic devices.


2021 ◽  
Vol 911 ◽  
Author(s):  
L.F. Chen ◽  
P.H. Taylor ◽  
D.Z. Ning ◽  
P.W. Cong ◽  
H. Wolgamot ◽  
...  
Keyword(s):  

Abstract


Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 704
Author(s):  
Wenjun An ◽  
Guquan Song ◽  
Shutong Chen

Given the influence of near-fault vertical seismic action, we established a girder-spring-damping-rod model of a double-span continuous girder bridge and used the transient wave function expansion method and indirect modal function method to calculate the seismic response of the bridge. We deduced the theoretical solution for the vertical and longitudinal contact force and displacement response of the bridge structure under the action of the near-fault vertical seismic excitation, and we analyzed the influence of the vertical separation of the bridge on the bending failure of the pier. Our results show that under the action of a near-fault vertical earthquake, pier-girder separation will significantly alter the bridge’s longitudinal displacement response, and that neglecting this separation may lead to the underestimation of the pier’s bending damage. Calculations of the bending moment at the bottom of the pier under different pier heights and cross-sectional diameters showed that the separation of the pier and the girder increases the bending moment at the pier’s base. Therefore, the reasonable design of the pier size and tensile support bearing in near-fault areas may help to reduce longitudinal damage to bridges.


2021 ◽  
Vol 160 ◽  
pp. 107874
Author(s):  
Tong-Chuan Che ◽  
Huan-Feng Duan ◽  
Pedro J. Lee

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 692
Author(s):  
Wenjun An ◽  
Guquan Song

To study the influence of the near-fault vertical earthquake, the beam-spring-damper-pier model is used to simulate the double-span continuous beam bridge. The transient wave function expansion method and the indirect mode function method are used to calculate the seismic response of the bridge. The theoretical solutions of the contact force and displacement response of the bridge under vertical earthquake excitation near-fault are derived. By using piers with three different heights, the influence of vertical separation on pier-bending failure is analyzed reasonably. The results show that under the near-fault earthquake action, the split has a certain influence on the pier failure. Moreover, the stiffness and damping of the bearing have an influence on the pier failure, and the change of the maximum pier height has different effects. Therefore, for bridges of different sizes, it is of great significance to select the appropriate stiffness and damping bearings to reduce pier failure.


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