Coastal dunes, as a whole, represent a natural barrier between the sea and the land, playing a vital role in the coastal defense against the waves and tides. Compared to the use of hard, man-made structures, not only is it a less expensive method to counteract the coastal erosion problems, but it is also a method that has higher ecological and scenic values in the environmental management aspec...

Wind-shield walls decrease the velocity of wind-drift sand flow in transit. This results in sand accumulating in the wind-shadow zone of both windshield wall and track line, causing severe sand sediment hazard. This study reveals the characteristics of sand accumulation and the laws of wind-blown sand removal in the wind-shadow areas of three different types of windshield walls, utilizing three...

erosion by wind is one of the most important factors in desert environment. prevailing winds can shift sand dunes and affect their accumulation. also, wind regime determines the direction of sand dune mobility. the aim of this research was to investigate sand drift potential using sand movement models. for this research, wind data between 1986 and 2005 from the meteorological station of yazd we...

Distinctive, eolian-dominated sandy deposits 35 m thick exposed along the SW margin of the Plio-Pleistocene Valdarno Basin in the Northern Apennines, Italy, reflect an unusually arid period in the region. Paleomagnetic investigation and Ar/Ar dating of a tephra layer, 10 m above the eolian sand, suggest that the sand was deposited between about 2.7 and 2.4 Ma. This age is coeval with the global...

An increase in intracellular Ca2+ concentration ([Ca2+]) and morphological were simultaneously observed by epifluorescence and differential interference contrast (DIC) microscopy during fertilization of the sand dollar, Clypeaster japonicus. [Ca2+], which was detected by a Ca2+ indicator, Fluo-3, initially increased just beneath the sperm-attached site on the egg surface 8.6 sec after attachmen...

We summarize information concerning Recent and Pleistocene-Holocene Uruguayan sand dollars (Mellitidae), as well as Miocene taxa (Monophorasteridae). Recent and Pleistocene-Holocene species (Encope emarginata, Mellita quinquiesperforata, and Leodia sexisperforata) are at their southernmost limits of distribution, with only E. emarginata recorded further south than Uruguay. Lower temperatures to...

Many larvae and other plankton have complex and variable morphologies of unknown functional significance. We experimentally and theoretically investigated the functional consequences of the complex morphologies of larval sand dollars, Dendraster excentricus (Eschscholtz), for hydrodynamic interactions between swimming and turbulent water motion. Vertical shearing flows (horizontal gradients of ...

In our present research, we focus on the modeling of airflow related to natural disasters, such assand accumulation, with urban form studies. The objective is to find which urban form can promote sand passing andreduce as much as possible stagnation of sand in the building area (streets, alleys, etc.). The urban form design will bediscussed through the simulation of airflow by using Computation...

Simple luminal obstructions of the large and small colon are relatively common causes of colic in horses, and are caused by feed impaction, sand accumulation, fibrous foreign body ingestion, nonstrangulating displacements, and or enterolith formation. Many horses with large colon and small colon feed impactions respond to medical treatment, including withholding feed, administering fluid therap...