scholarly journals Spectral and morpho-stratigraphic units integration on Apollo basin and Leibnitz/Von Karman craters on the Moon

2020 ◽  
Author(s):  
Francesca Zambon ◽  
Cristian Carli ◽  
Francesca Altieri ◽  
Jean-Philippe Combe ◽  
Carolyn H. van der Bogert ◽  
...  
Keyword(s):  
The Moon ◽  
Von Karman ◽  
Von Kármán

Topographic and Geomorphological Mapping and Analysis of the Chang'E-4 Landing Site on the Far Side of the Moon

2020 ◽  
Vol 86 (4) ◽  
pp. 247-258 ◽  
Author(s):  
Bo Wu ◽  
Fei Li ◽  
Han Hu ◽  
Yang Zhao ◽  
Yiran Wang ◽  
...  
Keyword(s):  
Landing Site ◽  
Joint Analysis ◽  
The Sun ◽  
The Moon ◽  
Soft Landing ◽  
Geomorphological Mapping ◽  
Von Karman ◽  
Lunar Reconnaissance Orbiter ◽  
Integrated Processing ◽  
Von Kármán

The Chinese lunar probe Chang'E-4 successfully landed in the Von Kármán crater on the far side of the Moon. This paper presents the topographic and geomorphological mapping and their joint analysis for selecting the Chang'E-4 landing site in the Von Kármán crater. A digital topographic model (<small>DTM</small>) of the Von Kármán crater, with a spatial resolution of 30 m, was generated through the integrated processing of Chang'E-2 images (7 m/pixel) and Lunar Reconnaissance Orbiter (<small>LRO</small>) Laser Altimeter (<small>LOLA</small>) data. Slope maps were derived from the <small>DTM</small>. Terrain occlusions to both the Sun and the relay satellite were studied. Craters with diameters ≥ 70 m were detected to generate a crater density map. Rocks with diameters ≥ 2 m were also extracted to generate a rock abundance map using an <small>LRO</small> narrow angle camera (<small>NAC</small>) image mosaic. The joint topographic and geomorphological analysis identified three subregions for landing. One of them, recommended as the highest-priority landing site, was the one in which Chang'E-4 eventually landed. After the successful landing of Chang'E-4, we immediately determined the precise location of the lander by the integrated processing of orbiter, descent and ground images. We also conducted a detailed analysis around the landing location. The results revealed that the Chang'E-4 lander has excellent visibility to the Sun and relay satellite; the lander is on a slope of about 4.5° towards the southwest, and the rock abundance around the landing location is almost 0. The developed methods and results can benefit future soft-landing missions to the Moon and other celestial bodies.

Intermittent volcanic activity detected in the Von Kármán crater on the farside of the Moon

2021 ◽  
Vol 569 ◽  
pp. 117062
Author(s):  
Yuefeng Yuan ◽  
Peimin Zhu ◽  
Long Xiao ◽  
Jun Huang ◽  
Edward J. Garnero ◽  
...  
Keyword(s):  
Volcanic Activity ◽  
The Moon ◽  
Von Karman ◽  
Von Kármán

A plagioclase-rich rock measured by Yutu-2 Rover in Von Kármán crater on the far side of the Moon

Icarus ◽  
2020 ◽  
Vol 350 ◽  
pp. 113901
Author(s):  
Pei Ma ◽  
Yuxue Sun ◽  
Meng-Hua Zhu ◽  
Yazhou Yang ◽  
Xiaoyi Hu ◽  
...  
Keyword(s):  
The Moon ◽  
Von Karman ◽  
Von Kármán

scholarly journals The two-dimensional hydrodynamical theory of moving aerofoils. IV

1947 ◽  
Vol 188 (1015) ◽  
pp. 439-463
Keyword(s):  
Stability Problem ◽  
Two Dimensional ◽  
Centre Of Gravity ◽  
First Approximation ◽  
Von Karman ◽  
Moving Cylinder ◽  
Period Equation ◽  
The Stability ◽  
Von Kármán ◽  
Hydrodynamical Theory

In the first part of this paper opportunity has been taken to make some adjustments in certain general formulae of previous papers, the necessity for which appeared in discussions with other workers on this subject. The general results thus amended are then applied to a general discussion of the stability problem including the effect of the trailing wake which was deliberately excluded in the previous paper. The general conclusion is that to a first approximation the wake, as usually assumed, has little or no effect on the reality of the roots of the period equation, but that it may introduce instability of the oscillations, if the centre of gravity of the element is not sufficiently far forward. During the discussion contact is made with certain partial results recently obtained by von Karman and Sears, which are shown to be particular cases of the general formulae. An Appendix is also added containing certain results on the motion of a vortex behind a moving cylinder, which were obtained to justify certain of the assumptions underlying the trail theory.

scholarly journals A Review on Analytical Modeling for Collapse Mode Capacitive Micromachined Ultrasonic Transducer of the Collapse Voltage and the Static Membrane Deflections

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 714
Author(s):  
Jiujiang Wang ◽  
Xin Liu ◽  
Yuanyu Yu ◽  
Yao Li ◽  
Ching-Hsiang Cheng ◽  
...  
Keyword(s):  
Analytical Modeling ◽  
Ultrasonic Transducer ◽  
Governing Equations ◽  
Von Karman ◽  
Von Kármán Equations ◽  
Collapse Mode ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
Gap Height ◽  
Von Kármán ◽  
Analytical Expressions

Analytical modeling of capacitive micromachined ultrasonic transducer (CMUT) is one of the commonly used modeling methods and has the advantages of intuitive understanding of the physics of CMUTs and convergent when modeling of collapse mode CMUT. This review article summarizes analytical modeling of the collapse voltage and shows that the collapse voltage of a CMUT correlates with the effective gap height and the electrode area. There are analytical expressions for the collapse voltage. Modeling of the membrane deflections are characterized by governing equations from Timoshenko, von Kármán equations and the 2D plate equation, and solved by various methods such as Galerkin’s method and perturbation method. Analytical expressions from Timoshenko’s equation can be used for small deflections, while analytical expression from von Kármán equations can be used for both small and large deflections.

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