scholarly journals Latitudinal Distribution of Ethane Precipitation on Titan Modulated by Topography and Orbital Forcing and Its Implication for Titan’s Surface Evolution

2021 ◽  
Vol 2 (3) ◽  
pp. 86
Author(s):  
Tetsuya Tokano
Keyword(s):  
Orbital Forcing ◽  
Latitudinal Distribution ◽  
Surface Evolution

scholarly journals A Method for Extracting Some Key Terrain Features from Shaded Relief of Digital Terrain Models

2020 ◽  
Vol 12 (17) ◽  
pp. 2809
Author(s):  
Meirman Syzdykbayev ◽  
Bobak Karimi ◽  
Hassan A. Karimi
Keyword(s):  
Land Surface ◽  
Basic Research ◽  
Probabilistic Methods ◽  
Detection Methods ◽  
Computational Techniques ◽  
Surface Evolution ◽  
Dem Analysis ◽  
High Degree ◽  
Terrain Features ◽  
Shaded Relief

Detection of terrain features (ridges, spurs, cliffs, and peaks) is a basic research topic in digital elevation model (DEM) analysis and is essential for learning about factors that influence terrain surfaces, such as geologic structures and geomorphologic processes. Detection of terrain features based on general geomorphometry is challenging and has a high degree of uncertainty, mostly due to a variety of controlling factors on surface evolution in different regions. Currently, there are different computational techniques for obtaining detailed information about terrain features using DEM analysis. One of the most common techniques is numerically identifying or classifying terrain elements where regional topologies of the land surface are constructed by using DEMs or by combining derivatives of DEM. The main drawbacks of these techniques are that they cannot differentiate between ridges, spurs, and cliffs, or result in a high degree of false positives when detecting spur lines. In this paper, we propose a new method for automatically detecting terrain features such as ridges, spurs, cliffs, and peaks, using shaded relief by controlling altitude and azimuth of illumination sources on both smooth and rough surfaces. In our proposed method, we use edge detection filters based on azimuth angle on shaded relief to identify specific terrain features. Results show that the proposed method performs similar to or in some cases better (when detecting spurs than current terrain features detection methods, such as geomorphon, curvature, and probabilistic methods.

Improved method of hydrous mineral detection by latitudinal distribution of 0.7-μm surface reflectance absorption on the asteroid Ryugu

Icarus ◽  
2021 ◽  
Vol 360 ◽  
pp. 114348
Author(s):  
Shingo Kameda ◽  
Yasuhiro Yokota ◽  
Toru Kouyama ◽  
Eri Tatsumi ◽  
Marika Ishida ◽  
...  
Keyword(s):  
Surface Reflectance ◽  
Latitudinal Distribution ◽  
Improved Method ◽  
Hydrous Mineral ◽  
Mineral Detection

scholarly journals In-Situ Laser Polishing Additive Manufactured AlSi10Mg: Effect of Laser Polishing Strategy on Surface Morphology, Roughness and Microhardness

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 393
Author(s):  
Jiantao Zhou ◽  
Xu Han ◽  
Hui Li ◽  
Sheng Liu ◽  
Shengnan Shen ◽  
...  
Keyword(s):  
Surface Quality ◽  
Molten Pool ◽  
Surface Defects ◽  
Polished Surface ◽  
Transient Model ◽  
Surface Evolution ◽  
Powder Bed ◽  
Laser Polishing ◽  
Surface Morphologies

Laser polishing is a widely used technology to improve the surface quality of the products. However, the investigation on the physical mechanism is still lacking. In this paper, the established numerical transient model reveals the rough surface evolution mechanism during laser polishing. Mass transfer driven by Marangoni force, surface tension and gravity appears in the laser-induced molten pool so that the polished surface topography tends to be smoother. The AlSi10Mg samples fabricated by laser-based powder bed fusion were polished at different laser hatching spaces, passes and directions to gain insight into the variation of the surface morphologies, roughness and microhardness in this paper. The experimental results show that after laser polishing, the surface roughness of Ra and Sa of the upper surface can be reduced from 12.5 μm to 3.7 μm and from to 29.3 μm to 8.4 μm, respectively, due to sufficient wetting in the molten pool. The microhardness of the upper surface can be elevated from 112.3 HV to 176.9 HV under the combined influence of the grain refinement, elements distribution change and surface defects elimination. Better surface quality can be gained by decreasing the hatching space, increasing polishing pass or choosing apposite laser direction.

Paleoclimate and sea level response to orbital forcing in the Middle Triassic of the eastern Tethys

2021 ◽  
pp. 103454
Author(s):  
Dongyang Liu ◽  
Chunju Huang ◽  
David B. Kemp ◽  
Mingsong Li ◽  
James G. Ogg ◽  
...  
Keyword(s):  
Sea Level ◽  
Middle Triassic ◽  
Orbital Forcing ◽  
And Sea Level
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