Shock Waves
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Chitrita Dasgupta ◽  
Sarit Maitra ◽  
Gadadhar Banerjee

2022 ◽  
Kun Han ◽  
Nan Kang ◽  
Xiaotong Yu ◽  
Jie Lu ◽  
Yuewen Ma

Abstract In previous studies, we found radial extracorporeal shock wave (rESW), can promote the proliferation of neural stem cells(NSCs). Emerging evidence suggests that lncRNA NEAT1 can regulate NSCs proliferation. Whether lncRNA NEAT1 plays a role in the proliferation of NSC induced by shock waves is unclear. Cell Counting Kit-8(CCK 8) method was used to detect the proliferation of NSCs, and the relative protein and mRNA expression of related genes of Nestin, Cyclin D1 and P21 were detected by Western Blot and Quantitative real-time PCR(RT-qPCR)respectively. Immunofluorescence staining was used to observe the changes in the number of BrdU/nestin positive cells. Overexpression of NEAT1 and let 7b in cells were used to explore whether rESW can rescue the decreased number of NSCs.We found that the optimal dose of R15 transmitter promoting NSCs proliferation is 1.5 bar, 500 pulse, 2 Hz. 1.2-1.5bar showed a dose-dependent effect on the proliferation of NSCs, but it was negatively correlated with the proliferation effect of NSC when it was more than 1.5bar. We revealed that let 7b-P21 axis was involved in regulating the inhibition of NSC proliferation which was activated by NEAT1 in NSCs. In addition, we demonstrated that rESW treatment resulted in the decrease of NEAT1 expression, which was accompanied by the improved biological function including proliferation.Our results confirm that low-intensity rESW(1.5bar,500pulse,2Hz) can promote the proliferation of NSCs through NEAT1-let 7b-P21 axis.

Galaxies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 10
Matthias Hoeft ◽  
Kamlesh Rajpurohit ◽  
Denis Wittor ◽  
Gabriella di Gennaro ◽  
Paola Domínguez-Fernández

Radio relics are extended radio emission features which trace shock waves in the periphery of galaxy clusters originating from cluster mergers. Some radio relics show a highly polarised emission, which make relics an excellent probe for the magnetisation of the intra-cluster medium. The origin of the relic polarisation is still debated. It could be a result of tangentially stretching the magnetic field at the shock surface. This scenario would naturally explain the alignment of the polarisation (E-vectors) with the shock normal. We have implemented a toy model for the relic polarisation according to this scenario. We find that the magnetic field strength itself crucially affects the fractional polarisation. Moreover, we find that the shock strength has surprisingly little effect on the overall polarisation fraction. Finally, we find that the fractional polarisation may decrease downstream depending on the magnetic field strength. Our results demonstrates that the shock compression scenario provides a very plausible explanation for the radio relic polarisation which specific features permitting to test the origin of radio relic polarisation.

2022 ◽  
Ioannis Kokkinakis ◽  
Dimitris Drikakis ◽  
Yun-qin He ◽  
Guo-zhu Liang

Abstract High-order simulations of supersonic combustion are presented to advance understanding of the complex chemically-reacting flow processes and identify unknown mechanisms of the high-speed combustion process. We have employed 11th-order accurate implicit large-eddy simulations in conjunction with thermochemistry models comprising 20 chemical reactions. We compare the computations with available experiments and discuss the accuracy and uncertainties in both. Jets emanating from above and below the hydrogen plumes influence the combustion process and accuracy of the predictions. The simulations reveal that high temperatures are sustained for a long-distance downstream of the combustion onset. A barycentric map for the Reynolds stresses is employed to analyse the turbulent anisotropy. We correlate the axisymmetric contraction and expansion of turbulence with the interaction of reflected-shock waves with the supersonic combustion hydroxyl production regions. The physics insights presented in this study could potentially lead to more efficient supersonic combustion and scramjet technologies.

2022 ◽  
Nicholas Kuenning ◽  
Isabelle C. Sanders ◽  
Tara Mellor ◽  
Nicolas Q. Minesi ◽  
Daniel I. Pineda ◽  

2022 ◽  
Vol 354 ◽  
pp. 00029
Adrian Bogdan Șimon-Marinică ◽  
Nicolae-Ioan Vlasin ◽  
Florin Manea ◽  
Dorin Popescu

In the following paper, experimental results regarding the effect of explosion pressure are obtained from open field experiments with detonation of explosive charges. In addition, sensors that can be used for security applications for the detection of toxic and explosive compounds, as well as mobile systems for the detection of shock waves due to explosions were used to acquire more detailed results. Sensors are the main components in products and systems used to detect chemicals and volatile organic compounds (VOCs) targeting applications in several fields, such as: industrial production and the automotive industry (detection of polluting gases from cars, medical applications, indoor air quality control. The sensory characteristics of a robot depend very much on its degree of autonomy, the applications for which it was designed and the type of work environment. The sensors can be divided into two categories: internal status sensors (sensors that provide information about the internal status of the mobile robot); external status sensors (sensors that provide information about the environment in which the robot operates). Another classification of these could be: distance sensors, position sensors, environmental sensors - sensors that provide information about various properties and characteristics of the environment (example: temperature, pressure, color, brightness), inertial sensors.

2022 ◽  
Vol 2022 (1) ◽  
Mike Blake ◽  
Richard A. Davison

Abstract We study the connection between many-body quantum chaos and energy dynamics for the holographic theory dual to the Kerr-AdS black hole. In particular, we determine a partial differential equation governing the angular profile of gravitational shock waves that are relevant for the computation of out-of-time ordered correlation functions (OTOCs). Further we show that this shock wave profile is directly related to the behaviour of energy fluctuations in the boundary theory. In particular, we demonstrate using the Teukolsky formalism that at complex frequency ω∗ = i2πT there exists an extra ingoing solution to the linearised Einstein equations whenever the angular profile of metric perturbations near the horizon satisfies this shock wave equation. As a result, for metric perturbations with such temporal and angular profiles we find that the energy density response of the boundary theory exhibit the signatures of “pole-skipping” — namely, it is undefined, but exhibits a collective mode upon a parametrically small deformation of the profile. Additionally, we provide an explicit computation of the OTOC in the equatorial plane for slowly rotating large black holes, and show that its form can be used to obtain constraints on the dispersion relations of collective modes in the dual CFT.

2022 ◽  
pp. 110913
Sandhya Chandrasekaran ◽  
Francisco Santibanez ◽  
Bharat B. Tripathi ◽  
Ryan DeRuiter ◽  
Ruth Vorder Bruegge ◽  

L. Lapostolle ◽  
K. Derrien ◽  
L. Morin ◽  
L. Berthe ◽  
O. Castelnau

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