in this report, we present a facile approach for the synthesis of luminescent cds and cds:mn+2 nanocrystals by reaction of cdso4 and na2s2o3 in the presence of thioglycerol (c3h8o2s) as capping agent. the influence of various experimental variables including, ph values and percentage of dopant, on the growth rate and optical properties of the obtained cds nanocrystals has been systematically in...

BACKGROUND Beach sand can harbor fecal indicator organisms and pathogens, but enteric illness risk associated with sand contact remains unclear. METHODS In 2007, visitors at 2 recreational marine beaches were asked on the day of their visit about sand contact. Ten to 12 days later, participants answered questions about health symptoms since the visit. F+ coliphage, Enterococcus, Bacteroidales...

abstract settling basins are essential hydraulic structures which have to be designed and constructed at all river water intakes to remove most of suspended sediments which enters the intake by flowing water. there have been many techniques for designing these structures. to simplifying the design procedure, some of these techniques have been applied many assumption and some others are so compl...

Previous research has shown that the temperature of underlying permafrost decreases after the ground surface is covered with sand. No significant conclusions have yet been drawn that explain why this happens, because the heat transfer mechanism effects of the sand layer on the underlying permafrost remain unclear. These mechanisms were studied in the present work. We found that the upward short...

In the evolution processes of wind blown sand movement and aeolian geomorphology, it always contains some complex behaviors, for example, the nonlinear character of turbulence and attractors, the stochastic character of wind gust, liftoff and movement of sand, the interaction among wind field, sand movement, electric field in wind blown sand flux and thermal diffusion, multi-scale character fro...

Straw checkerboard barrier (SCB) is the most representative antidesertification measure and plays a significant role in antidesertification projects. Large-eddy simulation and discrete-particle tracing were used to numerically simulate the wind sand movement inside the straw checkerboard barrier (SCB), study the movement characteristics of sand particles, find the transverse velocities of sand ...

We study the evolution of a one-dimensional pile, empty at rst, which receives a grain in its rst stack at each iteration. The nal position of grains is singular: grains are sorted according to their parity. They are sorted on trapezoidal areas alternating on both sides of a diagonal line of slope p 2. This is explained and proved by means of a local study. Each generated pile, encoded in heigh...

Abstract— In recent days the demand for river sand is increasing due to its lesser availability. Hence the practice of replacing river sand with M-Sand is taking a tremendous growth. It is also inferred from the literature that replacement of normal sand with M-Sand produces no appreciable increase in compressive strength due to the variation in the pore size of concrete at micro level. This pa...

Sediment deprivation from dam installments contributes to beach erosion yet the underlying physical and economic factors linking them together have traditionally been isolated during regional planning. In order to gain a better understanding of the behavior of a managed beach system, a dynamic simulation model was developed incorporating physical and monetary factors influencing the amount of a...

twin reversed arterial perfusion (trap) sequence is a syndrome with poor prognosis, seen only in monochorionic monozygotic twin pregnancies. the incidence is one in 35.000 births and one in 100 monozygotic twin pregnancies. it is characterized with a recipient fetus exhibiting lethal anomalies including acardia and a pump fetus. mortality is usually due to heart failure or premature labor cause...