Moving sand dunes represent a natural phenomenon in most arid and hyper-arid sand deserts, such as the Sahara, Namib, Taklamakan and Rub'al Khali. The preconditions for large sand dunes or even extensive “sand seas” are, on the one hand, the...

In conclusion, we learned that because of the different physical and chemical properties of mixtures, it is possible for us to separate a solution into its original components. In our several experiments, we used chemical and physical means to partially and wholly separate components in …

From the performed research the following general conclusions can be drawn: Both the measured cutting forces as the measured water sub-pressures agree reasonably with the theory. For both sand types is observed that the cutting forces and the water sub-pressures become smaller in comparison with the theory, when the blade angle becomes larger.

2021年4月2日 · The reading of the sand literature leads to the following conclusions. Despite this socioeconomic importance and controversial socioecological effects, academic research on sand has largely taken place in the natural sciences (geomorphology, biology, geology) and selectively in engineering and law.

2014年1月1日 · On Venus, with the thickest atmosphere of all, large dunes are scarce because that world is starved of sand. Mars’ young dunes and ripples are generally larger than young dunes on Earth, because the thin atmosphere is associated with longer dynamic length scales (saltation trajectories and saturation length).

A paradigm of infinite sand resources still dominates. Challenging this is the difficult task ahead as we aim for a rapid yet smooth transition to more sustainable sourcing, while reducing consumption and demand in parallel.

This experiment uses sand replacement cylinders to determine the in situ density of natural or compacted soils. The dry density of a soil is related to its moisture content, where lower moisture content results in higher dry density. To accurately measure density, the excavated hole must match the volume of the calibration container used.

In conclusion, sand, silt, clay, and organic matter make up all soils, but it is the amount of each of these particles that tells us what kind of soil we have. Sandy soil, clay soil, and loam soil all soak up water differently. Just like air, we don't think about soil often, but it is extremely important to plants, animals, and the whole world.

Conclusion. The study presented in this paper showed clearly that the frequency and intensity of dry and wet spells returned can differ widely between RPs. For our three sites, it appears overall that RPs overestimate the number of rainy days and therefore wet …